Human: Difference between revisions

{{Short description|Species of hominid in the genus Homo}}

| name = Human<ref name=msw3>{{MSW3 Groves | pages = | id = 12100795 | name-list-style = vanc }}</ref>

| fossil_range = {{Fossil range|0.300|0}} <small>[[Chibanian]] – [[Holocene|Present]]</small>

| image_caption = An [[adult]] human [[man|male]] (left) and [[woman|female]] ([[Thailand]], 2007)

| subdivision_ranks = Subspecies

| range_map_caption = ''Homo sapiens'' population density (2005)

| synonyms =  

'''Humans''' (''Homo sapiens'') are the most abundant and widespread [[species]] of [[primate]], characterized by [[bipedality|bipedalism]] and large, complex [[brain]]s. This has enabled the development of advanced [[tools]], [[culture]], and [[language]]. Humans are highly social and tend to live in complex [[social structure]]s composed of many cooperating and competing groups, from [[family|families]] and [[kinship]] networks to political [[state (polity)|states]]. [[Social interaction]]s between humans have established a wide variety of values, [[norm (sociology)|social norms]], and [[ritual]]s, which bolster human [[society]]. Curiosity and the human desire to understand and influence the environment and to explain and manipulate [[Phenomenon|phenomena]] have motivated humanity's development of [[science]], [[philosophy]], [[mythology]], [[religion]], and other fields of study.

Although some scientists equate the term ''humans'' with all members of the genus ''[[Homo]]'', in common usage it generally refers to ''Homo sapiens'', the only [[Extant taxon|extant]] member. [[Anatomically modern human]]s emerged around 300,000 years ago in Africa, evolving from ''[[Homo heidelbergensis]]'' or a similar species and migrating [[Recent African origin of modern humans|out of Africa]], gradually replacing local populations of [[archaic humans]]. For most of history, all humans were [[nomadic]] hunter-gatherers. Humans began exhibiting [[behavioral modernity]] about 160,000-60,000 years ago. The [[Neolithic Revolution]], which began in [[Southwest Asia]] around 13,000 years ago (and separately in a few other places), saw the emergence of [[agriculture]] and permanent [[human settlement]]. As populations became larger and denser, forms of governance developed within and between communities and a number of [[civilization]]s have risen and fallen. Humans have continued to expand, with a global population of over 7.9 billion as of 2022.

[[Gene]]s and the [[Environment (biophysical)|environment]] influence human biological variation in visible characteristics, physiology, disease susceptibility, mental abilities, body size and life span. Though humans vary in many traits (such as genetic predispositions and physical features), any two humans are at least 99% genetically similar. Humans [[sex differences in humans|are sexually dimorphic]]: generally, men have greater body strength and women have a higher [[body fat]] percentage. At puberty, humans develop [[secondary sex characteristic]]s. Women are capable of [[pregnancy]], and undergo [[menopause]] and become [[Infertility|infertile]] at around the age of 50.

Humans are [[omnivorous]], capable of consuming a wide variety of plant and animal material, and have [[Control of fire by early humans|used fire]] and other forms of heat to prepare and [[cooking|cook]] food since the time of ''H. erectus''. They can survive for up to eight weeks without food, and three or four days without water. Humans are generally [[Diurnality|diurnal]], sleeping on average seven to nine hours per day. [[Childbirth]] is dangerous, with a high risk of complications and death. Often, both the mother and the father provide care for their children, who are [[Altricial|helpless at birth]].

Humans have a large and highly developed [[prefrontal cortex]], the region of the brain associated with higher [[cognition]]. They are intelligent, capable of [[episodic memory#In animals|episodic memory]], have flexible facial expressions, [[self-awareness]] and a [[theory of mind]]. The human mind is capable of [[introspection]], private [[thought]], [[imagination]], [[Volition (psychology)|volition]] and forming views on [[existence]]. This has allowed great technological advancements and complex tool development possible through reason and the transmission of knowledge to future generations. Language, art and trade are defining characteristics of humans. Long-distance trade routes might have led to [[cultural explosion]]s and resource distribution that gave humans an advantage over other similar species.

All modern humans are classified into the [[species]] ''Homo sapiens'', coined by [[Carl Linnaeus]] in his 18th-century work ''[[Systema Naturae]]''.<ref>{{cite journal| vauthors = Spamer EE |date=29 January 1999|title=Know Thyself: Responsible Science and the Lectotype of Homo sapiens Linnaeus, 1758|journal=Proceedings of the Academy of Natural Sciences |volume=149 |issue=1 |pages=109–14 |jstor=4065043}}</ref> The [[Name of a biological genus|generic name]] "''[[Homo]]''" is a learned 18th-century derivation from Latin {{lang|la|homō}}, which refers to humans of either sex.<ref>[[IEW|Porkorny (1959)]] s.v. "g'hðem" pp. 414–16; "Homo." Dictionary.com Unabridged (v 1.1). Random House, Inc. 23 September 2008. {{cite dictionary|url=https://dictionary.reference.com/browse/Homo|dictionary=Dictionary.com|title=Homo|url-status=live|archive-url=https://web.archive.org/web/20080927011551/https://dictionary.reference.com/browse/homo|archive-date=27 September 2008}}</ref> The word ''human'' can refer to all members of the ''Homo'' genus,<ref name="auto">{{cite web| vauthors = Barras C |title=We don't know which species should be classed as 'human'|url=https://www.bbc.com/earth/story/20160111-what-is-it-that-makes-you-a-human-and-not-something-else|access-date=2021-03-31|website=www.bbc.com|language=en}}</ref> although in common usage it generally just refers to ''Homo sapiens,'' the only extant species.<ref>{{cite web|title=Definition of HUMAN|url=https://www.merriam-webster.com/dictionary/human|access-date=2021-03-31|website=www.merriam-webster.com|language=en}}</ref> The name "''Homo'' ''sapiens''" means 'wise man' or 'knowledgeable man'.<ref>{{Cite journal| vauthors = Spamer EE |date=1999|title=Know Thyself: Responsible Science and the Lectotype of Homo sapiens Linnaeus, 1758 |url= https://www.jstor.org/stable/4065043 |journal=Proceedings of the Academy of Natural Sciences of Philadelphia |volume=149 |pages=109–114|issn=0097-3157|jstor=4065043}}</ref> There is disagreement if certain extinct members of the genus, namely [[Neanderthal]]s, should be included as a separate species of humans or as a [[subspecies]] of ''H. sapiens''.<ref name="auto"/>

''Human'' is a [[loanword]] of [[Middle English]] from [[Old French]] {{lang|fro|humain}}, ultimately from [[Latin]] {{lang|la|hūmānus}}, the adjectival form of {{lang|la|homō}} ('man' — in the sense of humankind).<ref>[[OED]], [[Sub verbo|s.v.]] "human."</ref> The native English term ''[[Man (word)|man]]'' can refer to the species generally (a synonym for ''humanity'') as well as to human males. It may also refer to individuals of either sex, though this form is less common in contemporary English.<ref>{{cite web |url=https://www.merriam-webster.com/dictionary/man |title= Man | quote = Definition 2: a man belonging to a particular category (as by birth, residence, membership, or occupation) —usually used in combination | work = Merriam-Webster Dictionary |archive-date=22 September 2017 |archive-url=https://web.archive.org/web/20170922050822/https://www.merriam-webster.com/dictionary/man |url-status= live | access-date = 14 September 2017 }}</ref>

Despite the fact that the word ''animal'' is colloquially used as an [[Opposite (semantics)|antonym]] for ''human'',<ref>{{Cite web |title=Thesaurus results for HUMAN |url=https://www.merriam-webster.com/thesaurus/human |access-date=2022-05-21 |website=www.merriam-webster.com |language=en}}</ref> and contrary to a [[List of common misconceptions|common biological misconception]], humans are animals.<ref>{{Cite web |date=2021-09-19 |title=Misconceptions about evolution - Understanding Evolution |url=https://evolution.berkeley.edu/teach-evolution/misconceptions-about-evolution/ |access-date=2022-05-21 |language=en-US}}</ref> The word ''[[person]]'' is often used interchangeably with ''human'', but philosophical debate exists as to whether personhood applies to all humans or all sentient beings, and further if one can lose personhood (such as by going into a [[persistent vegetative state]]).<ref>{{Cite web|title=Concept of Personhood - MU School of Medicine|url=https://medicine.missouri.edu/centers-institutes-labs/health-ethics/faq/personhood|access-date=2021-07-04|website=medicine.missouri.edu}}</ref>

Humans are apes ([[Hominoidea|superfamily Hominoidea]]).<ref>{{Cite book| vauthors = Tuttle RH |title=International Encyclopedia of Biological Anthropology|date=2018-10-04|publisher=[[John Wiley & Sons, Inc.]]|isbn=978-1-118-58442-2| veditors = Trevathan W, Cartmill M, Dufour D, Larsen C |place=[[Hoboken]], [[New Jersey]], [[United States]]|pages=1–2|language=en|chapter=Hominoidea: conceptual history|doi=10.1002/9781118584538.ieba0246|s2cid=240125199|author-link=Russell Tuttle|access-date=2021-05-26|chapter-url=https://doi.wiley.com/10.1002/9781118584538.ieba0246}}</ref> The [[Lineage (evolution)|lineage]] of apes that eventually gave rise to humans first split from gibbons (family [[Hylobatidae]]) and [[orangutan]]s (genus ''Pongo''), then [[gorilla]]s (genus ''Gorilla''), and finally, [[chimpanzee]]s and [[Bonobo|bonobos]] (genus ''[[Pan (genus)|Pan]]''). The last split, between the human and chimpanzee–bonobo lineages, took place around 8–4 million years ago, in the late [[Miocene]] epoch.<ref>{{cite journal|vauthors=Tattersall I, Schwartz J|year=2009|title=Evolution of the Genus ''Homo''|journal=Annual Review of Earth and Planetary Sciences|volume=37|issue=1|pages=67–92|bibcode=2009AREPS..37...67T|doi=10.1146/annurev.earth.031208.100202}}</ref><ref>{{cite journal | vauthors = Goodman M, Tagle DA, Fitch DH, Bailey W, Czelusniak J, Koop BF, Benson P, Slightom JL | display-authors = 6 | title = Primate evolution at the DNA level and a classification of hominoids | journal = Journal of Molecular Evolution | volume = 30 | issue = 3 | pages = 260–6 | date = March 1990 | pmid = 2109087 | doi = 10.1007/BF02099995 | s2cid = 2112935 | bibcode = 1990JMolE..30..260G }}</ref><ref name="Ruvolo1997">{{cite journal|vauthors=Ruvolo M|date=March 1997|title=Molecular phylogeny of the hominoids: inferences from multiple independent DNA sequence data sets|journal=Molecular Biology and Evolution |volume=14 |issue=3 |pages=248–65|doi=10.1093/oxfordjournals.molbev.a025761|pmid=9066793|doi-access=free}}</ref><ref>{{cite journal | vauthors = Brahic C |title=Our True Dawn |journal=New Scientist|volume=216 |issue=2892 |pages=34–37 |year=2012 |doi=10.1016/S0262-4079(12)63018-8 |bibcode= 2012NewSc.216...34B }}</ref> During this split, [[chromosome 2]] was formed from the joining of two other chromosomes, leaving humans with only 23 pairs of chromosomes, compared to 24 for the other apes.<ref name="fusion">{{cite web|title=Human Chromosome 2 is a fusion of two ancestral chromosomes|url=https://www.evolutionpages.com/chromosome_2.htm|archive-url=https://web.archive.org/web/20110809040210/https://www.evolutionpages.com/chromosome_2.htm|archive-date=9 August 2011|access-date=18 May 2006|work=Evolution pages|vauthors=MacAndrew A}}</ref> Following their split with chimpanzees and bonobos, the [[Hominini|hominins]] diversified into many species and at least two distinct genera. All but one of these lineages—representing the genus ''[[Homo]]'' and its sole extant species ''Homo sapiens''—is now extinct.<ref>{{Cite web |last=McNulty |first=Kieran P. |year=2016 |title=Hominin Taxonomy and Phylogeny: What's In A Name? |url=https://www.nature.com/scitable/knowledge/library/hominin-taxonomy-and-phylogeny-what-s-in-142102877/ |access-date=2022-06-11 |website=Nature Education Knowledge |language=en}}</ref>

      |1=Hylobatidae ([[gibbon]]s)

      |label2=Hominidae (hominids, [[great ape]]s)

        |label1=Pongo ([[orangutan]]s)

[[File:Lucy Skeleton.jpg|thumb|left|upright|Reconstruction of [[Lucy (Australopithecus)|Lucy]]'','' the first ''[[Australopithecus afarensis]]'' skeleton found ]]

The genus ''Homo'' evolved from ''[[Australopithecus]]''.<ref>{{cite journal | vauthors = Strait DS |title=The Evolutionary History of the Australopiths |journal=Evolution: Education and Outreach |date=September 2010 |volume=3 |issue=3 |pages=341–352 |doi=10.1007/s12052-010-0249-6 |s2cid=31979188 |url=https://evolution-outreach.biomedcentral.com/articles/10.1007/s12052-010-0249-6 |language=en |issn=1936-6434}}</ref><ref>{{cite journal | vauthors = Dunsworth HM |title=Origin of the Genus Homo |journal=Evolution: Education and Outreach |date=September 2010 |volume=3 |issue=3 |pages=353–366 |doi=10.1007/s12052-010-0247-8 |s2cid=43116946 |url=https://evolution-outreach.biomedcentral.com/articles/10.1007/s12052-010-0247-8 |language=en |issn=1936-6434}}</ref> Though [[Human fossils|fossils]] from the transition are scarce, the earliest members of ''Homo'' share several key traits with ''Australopithecus''.<ref>{{cite journal | vauthors = Kimbel WH, Villmoare B | title = From Australopithecus to Homo: the transition that wasn't | journal = Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences | volume = 371 | issue = 1698 | page = 20150248 | date = July 2016 | pmid = 27298460 | pmc = 4920303 | doi = 10.1098/rstb.2015.0248 | s2cid = 20267830 }}</ref><ref name=Villmoare2015>{{cite journal | vauthors = Villmoare B, Kimbel WH, Seyoum C, Campisano CJ, DiMaggio EN, Rowan J, Braun DR, Arrowsmith JR, Reed KE | display-authors = 6 | title = Paleoanthropology. Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia | journal = Science | volume = 347 | issue = 6228 | pages = 1352–1355 | date = March 2015 | pmid = 25739410 | doi = 10.1126/science.aaa1343 | doi-access = free | bibcode = 2015Sci...347.1352V }}</ref> The earliest record of ''Homo'' is the 2.8 million-year-old specimen [[LD 350-1]] from Ethiopia, and the earliest named species are ''[[Homo habilis]]'' and ''[[Homo rudolfensis]]'' which evolved by 2.3 million years ago.<ref name=Villmoare2015 /> ''[[Homo erectus|H. erectus]]'' (the African variant is sometimes called ''[[Homo ergaster|H. ergaster]]'') evolved 2 million years ago and was the first [[archaic human]] species to leave Africa and disperse across Eurasia.<ref>{{cite journal | vauthors = Zhu Z, Dennell R, Huang W, Wu Y, Qiu S, Yang S, Rao Z, Hou Y, Xie J, Han J, Ouyang T | display-authors = 6 | title = Hominin occupation of the Chinese Loess Plateau since about 2.1 million years ago | journal = Nature | volume = 559 | issue = 7715 | pages = 608–612 | date = July 2018 | pmid = 29995848 | doi = 10.1038/s41586-018-0299-4 | bibcode = 2018Natur.559..608Z | s2cid = 49670311 }}</ref> ''H. erectus'' also was the first to evolve a characteristically human [[body plan]]. ''Homo sapiens'' emerged in Africa around 300,000 years ago from a species commonly designated as either ''[[Homo heidelbergensis|H. heidelbergensis]]'' or ''[[Homo rhodesiensis|H. rhodesiensis]]'', the descendants of ''H. erectus'' that remained in Africa.<ref>{{cite journal | vauthors = Hublin JJ, Ben-Ncer A, Bailey SE, Freidline SE, Neubauer S, Skinner MM, Bergmann I, Le Cabec A, Benazzi S, Harvati K, Gunz P | display-authors = 6 | title = New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens | journal = Nature | volume = 546 | issue = 7657 | pages = 289–292 | date = June 2017 | pmid = 28593953 | doi = 10.1038/nature22336 | bibcode = 2017Natur.546..289H | url = https://kar.kent.ac.uk/62267/1/Submission_288356_1_art_file_2637492_j96j1b.pdf }}</ref> ''H. sapiens'' migrated out of the continent, gradually replacing local populations of archaic humans.<ref>{{cite journal|author=<!--Staff writer(s); no by-line.-->|date=May 13, 2005|title=Out of Africa Revisited|journal=[[Science (journal)|Science]]|type=This Week in ''Science''|volume=308|issue=5724|page=921|doi=10.1126/science.308.5724.921g|issn=0036-8075|s2cid=220100436}}</ref><ref>{{cite journal | vauthors = Stringer C | title = Human evolution: Out of Ethiopia | journal = Nature | volume = 423 | issue = 6941 | pages = 692–3, 695 | date = June 2003 | pmid = 12802315 | doi = 10.1038/423692a | s2cid = 26693109 | author-link = Chris Stringer | bibcode = 2003Natur.423..692S }}</ref><ref>{{cite web| vauthors = Johanson D |author-link=Donald Johanson|date=May 2001|title=Origins of Modern Humans: Multiregional or Out of Africa?|url=https://www.actionbioscience.org/evolution/johanson.html|access-date=November 23, 2009|website=[[actionbioscience]]|publisher=[[American Institute of Biological Sciences]]|location=Washington, DC}}</ref> Humans began exhibiting [[behavioral modernity]] about 160,000-70,000 years ago,<ref name="Marean et al 2007">{{cite journal |last1=Marean |first1=Curtis |display-authors=etal |date=2007 |title=Early human use of marine resources and pigment in South Africa during the Middle Pleistocene |journal=Nature |volume=449 |issue=7164 |pages=905–908 |bibcode=2007Natur.449..905M |doi=10.1038/nature06204 |pmid=17943129 |s2cid=4387442}}</ref> and possibly earlier.<ref name="Brooks">{{Cite journal |vauthors=Brooks AS, Yellen JE, Potts R, Behrensmeyer AK, Deino AL, Leslie DE, Ambrose SH, Ferguson JR, d'Errico F, Zipkin AM, Whittaker S, Post J, Veatch EG, Foecke K, Clark JB |year=2018 |title=Long-distance stone transport and pigment use in the earliest Middle Stone Age |journal=Science |volume=360 |issue=6384 |pages=90–94 |bibcode=2018Sci...360...90B |doi=10.1126/science.aao2646 |pmid=29545508 |doi-access=free}}</ref>  

The [[Recent African origin of modern humans|"out of Africa" migration]] took place in at least two waves, the first around 130,000 to 100,000 years ago, the second ([[Southern Dispersal]]) around 70,000 to 50,000 years ago.<ref name="Posth">{{cite journal | vauthors = Posth C, Renaud G, Mittnik A, Drucker DG, Rougier H, Cupillard C, Valentin F, Thevenet C, Furtwängler A, Wißing C, Francken M, Malina M, Bolus M, Lari M, Gigli E, Capecchi G, Crevecoeur I, Beauval C, Flas D, Germonpré M, van der Plicht J, Cottiaux R, Gély B, Ronchitelli A, Wehrberger K, Grigorescu D, Svoboda J, Semal P, Caramelli D, Bocherens H, Harvati K, Conard NJ, Haak W, Powell A, Krause J | display-authors = 6 | title = Pleistocene Mitochondrial Genomes Suggest a Single Major Dispersal of Non-Africans and a Late Glacial Population Turnover in Europe | journal = Current Biology | volume = 26 | issue = 6 | pages = 827–33 | date = March 2016 | pmid = 26853362 | doi = 10.1016/j.cub.2016.01.037 | hdl-access = free | s2cid = 140098861 | hdl = 2440/114930 }}</ref><ref>{{cite journal | vauthors = Karmin M, Saag L, Vicente M, Wilson Sayres MA, Järve M, Talas UG, Rootsi S, Ilumäe AM, Mägi R, Mitt M, Pagani L, Puurand T, Faltyskova Z, Clemente F, Cardona A, Metspalu E, Sahakyan H, Yunusbayev B, Hudjashov G, DeGiorgio M, Loogväli EL, Eichstaedt C, Eelmets M, Chaubey G, Tambets K, Litvinov S, Mormina M, Xue Y, Ayub Q, Zoraqi G, Korneliussen TS, Akhatova F, Lachance J, Tishkoff S, Momynaliev K, Ricaut FX, Kusuma P, Razafindrazaka H, Pierron D, Cox MP, Sultana GN, Willerslev R, Muller C, Westaway M, Lambert D, Skaro V, Kovačevic L, Turdikulova S, Dalimova D, Khusainova R, Trofimova N, Akhmetova V, Khidiyatova I, Lichman DV, Isakova J, Pocheshkhova E, Sabitov Z, Barashkov NA, Nymadawa P, Mihailov E, Seng JW, Evseeva I, Migliano AB, Abdullah S, Andriadze G, Primorac D, Atramentova L, Utevska O, Yepiskoposyan L, Marjanovic D, Kushniarevich A, Behar DM, Gilissen C, Vissers L, Veltman JA, Balanovska E, Derenko M, Malyarchuk B, Metspalu A, Fedorova S, Eriksson A, Manica A, Mendez FL, Karafet TM, Veeramah KR, Bradman N, Hammer MF, Osipova LP, Balanovsky O, Khusnutdinova EK, Johnsen K, Remm M, Thomas MG, Tyler-Smith C, Underhill PA, Willerslev E, Nielsen R, Metspalu M, Villems R, Kivisild T | display-authors = 6 | title = A recent bottleneck of Y chromosome diversity coincides with a global change in culture | journal = Genome Research | volume = 25 | issue = 4 | pages = 459–66 | date = April 2015 | pmid = 25770088 | pmc = 4381518 | doi = 10.1101/gr.186684.114 }}</ref> ''H. sapiens'' proceeded to colonize all the continents and larger islands, arriving in [[Eurasia]] 60,000 years ago,<ref>{{cite journal | vauthors = Armitage SJ, Jasim SA, Marks AE, Parker AG, Usik VI, Uerpmann HP | title = The southern route "out of Africa": evidence for an early expansion of modern humans into Arabia | journal = Science | volume = 331 | issue = 6016 | pages = 453–6 | date = January 2011 | pmid = 21273486 | doi = 10.1126/science.1199113 | url = https://www.sciencenews.org/view/generic/id/69197/title/Hints_of_earlier_human_exit_from_Africa | url-status = live | access-date = 1 May 2011 | bibcode = 2011Sci...331..453A | s2cid = 20296624 | archive-url = https://web.archive.org/web/20110427201317/https://www.sciencenews.org/view/generic/id/69197/title/Hints_of_earlier_human_exit_from_Africa | archive-date = 27 April 2011 }}</ref><ref>{{cite web | vauthors = Rincon P | url = https://www.bbc.co.uk/news/science-environment-12300228 | title = Humans 'left Africa much earlier' | archive-url = https://web.archive.org/web/20120809051349/https://www.bbc.co.uk/news/science-environment-12300228| archive-date=9 August 2012 | work = BBC News | date = 27 January 2011 }}</ref> Australia around 65,000 years ago,<ref>{{cite journal | vauthors = Clarkson C, Jacobs Z, Marwick B, Fullagar R, Wallis L, Smith M, Roberts RG, Hayes E, Lowe K, Carah X, Florin SA, McNeil J, Cox D, Arnold LJ, Hua Q, Huntley J, Brand HE, Manne T, Fairbairn A, Shulmeister J, Lyle L, Salinas M, Page M, Connell K, Park G, Norman K, Murphy T, Pardoe C | display-authors = 6 | title = Human occupation of northern Australia by 65,000 years ago | journal = Nature | volume = 547 | issue = 7663 | pages = 306–310 | date = July 2017 | pmid = 28726833 | doi = 10.1038/nature22968 | bibcode = 2017Natur.547..306C | s2cid = 205257212 | hdl = 2440/107043 }}</ref> the Americas around 15,000 years ago, and remote islands such as Hawaii, [[Easter Island]], [[Madagascar]], and [[New Zealand]] between the years 300 and 1280 CE.<ref name="Lowe">{{cite web| vauthors = Lowe DJ |year=2008|title=Polynesian settlement of New Zealand and the impacts of volcanism on early Maori society: an update|url=https://researchcommons.waikato.ac.nz/bitstream/10289/2690/1/Lowe%202008%20Polynesian%20settlement%20guidebook.pdf|url-status=live|archive-url=https://web.archive.org/web/20100522032853/https://researchcommons.waikato.ac.nz/bitstream/10289/2690/1/Lowe%202008%20Polynesian%20settlement%20guidebook.pdf|archive-date=22 May 2010|access-date=29 April 2010|publisher=University of Waikato}}</ref><ref>{{cite journal | vauthors = Appenzeller T | title = Human migrations: Eastern odyssey | journal = Nature | volume = 485 | issue = 7396 | pages = 24–6 | date = May 2012 | pmid = 22552074 | doi = 10.1038/485024a | bibcode = 2012Natur.485...24A | doi-access = free }}</ref>

Human evolution was not a simple linear or branched progression but involved [[Interbreeding between archaic and modern humans|interbreeding between related species]].<ref name="pmid21179161"/><ref>{{cite journal | url = https://www.grochbiology.org/EarlyHominidInterbreeding.pdf | title = Human Hybrids | archive-url = https://web.archive.org/web/20180824034550/https://www.grochbiology.org/EarlyHominidInterbreeding.pdf| archive-date=24 August 2018 | vauthors = Hammer MF | journal = Scientific American | date = May 2013 | volume = 308 | issue = 5 | pages = 66–71 | doi = 10.1038/scientificamerican0513-66 | pmid = 23627222 | bibcode = 2013SciAm.308e..66H }}</ref><ref>{{cite journal| vauthors = Yong E |date=July 2011|title=Mosaic humans, the hybrid species|journal=New Scientist |volume=211 |issue=2823 |pages=34–38|bibcode=2011NewSc.211...34Y|doi=10.1016/S0262-4079(11)61839-3}}</ref> Genomic research has shown that hybridization between substantially diverged lineages was common in human evolution.<ref name="Ackermann 2015">{{cite journal| vauthors = Ackermann RR, Mackay A, Arnold ML |date=October 2015|title=The Hybrid Origin of "Modern" Humans|journal=Evolutionary Biology|volume=43|issue=1|pages=1–11|doi=10.1007/s11692-015-9348-1|s2cid=14329491}}</ref> [[DNA]] evidence suggests that several genes of [[Neanderthal]] origin are present among all non-African populations, and Neanderthals and other hominins, such as [[Denisovan]]s, may have contributed up to 6% of their [[genome]] to present-day humans.<ref name="pmid21179161">{{cite journal | vauthors = Reich D, Green RE, Kircher M, Krause J, Patterson N, Durand EY, Viola B, Briggs AW, Stenzel U, Johnson PL, Maricic T, Good JM, Marques-Bonet T, Alkan C, Fu Q, Mallick S, Li H, Meyer M, Eichler EE, Stoneking M, Richards M, Talamo S, Shunkov MV, Derevianko AP, Hublin JJ, Kelso J, Slatkin M, Pääbo S | display-authors = 6 | title = Genetic history of an archaic hominin group from Denisova Cave in Siberia | journal = Nature | volume = 468 | issue = 7327 | pages = 1053–60 | date = December 2010 | pmid = 21179161 | pmc = 4306417 | doi = 10.1038/nature09710 | bibcode = 2010Natur.468.1053R | hdl = 10230/25596 | author-link1 = David Reich (geneticist) }}</ref><ref name="pmid20439435">{{cite journal | vauthors = Noonan JP | title = Neanderthal genomics and the evolution of modern humans | journal = Genome Research | volume = 20 | issue = 5 | pages = 547–53 | date = May 2010 | pmid = 20439435 | pmc = 2860157 | doi = 10.1101/gr.076000.108 }}</ref><ref name="10.1126/science.1209202">{{cite journal | vauthors = Abi-Rached L, Jobin MJ, Kulkarni S, McWhinnie A, Dalva K, Gragert L, Babrzadeh F, Gharizadeh B, Luo M, Plummer FA, Kimani J, Carrington M, Middleton D, Rajalingam R, Beksac M, Marsh SG, Maiers M, Guethlein LA, Tavoularis S, Little AM, Green RE, Norman PJ, Parham P | display-authors = 6 | title = The shaping of modern human immune systems by multiregional admixture with archaic humans | journal = Science | volume = 334 | issue = 6052 | pages = 89–94 | date = October 2011 | pmid = 21868630 | pmc = 3677943 | doi = 10.1126/science.1209202 | bibcode = 2011Sci...334...89A }}</ref>

Human evolution is characterized by a number of [[morphology (biology)|morphological]], [[human development (biology)|developmental]], [[human physiology|physiological]], and [[Human behavior|behavioral]] changes that have taken place since the split between the [[chimpanzee-human last common ancestor|last common ancestor of humans and chimpanzees]]. The most significant of these adaptations are obligate bipedalism, increased brain size and decreased [[sexual dimorphism]] ([[neoteny]]). The relationship between all these changes is the subject of ongoing debate.<ref name="Boyd2003">{{cite book| vauthors = Boyd R, Silk JB |author1-link=Robert Boyd (anthropologist)|author2-link=Joan Silk|url=https://archive.org/details/howhumansevolved03edboyd|title=How Humans Evolved|publisher=Norton|year=2003|isbn=978-0-393-97854-4|location=New York City|url-access=registration}}</ref>

[[File:Early migrations mercator.svg|thumb|350px|Overview map of the peopling of the world by [[Early human migrations|early human migration]]  during the [[Upper Paleolithic]], following to the [[Southern Dispersal]] paradigm.]]

Until about 12,000 years ago, all humans lived as [[hunter-gatherer]]s.<ref>{{Cite book| vauthors = Garcea E |url=https://oxfordhandbooks.com/view/10.1093/oxfordhb/9780199569885.001.0001/oxfordhb-9780199569885-e-29|title=Hunter-Gatherers of the Nile Valley and the Sahara Before 12,000 Years Ago|date=2013-07-04|publisher=Oxford University Press|doi=10.1093/oxfordhb/9780199569885.013.0029}}</ref> The [[Neolithic Revolution]] (the invention of [[agriculture]]) first took place in [[Southwest Asia]] and spread through large parts of the [[Old World]] over the following millennia.<ref>{{Cite book| vauthors = Colledge S, Conolly J, Dobney K, Manning K, Shennan S |url=https://www.worldcat.org/oclc/855969933|title=Origins and Spread of Domestic Animals in Southwest Asia and Europe.|date=2013|publisher=Left Coast Press|isbn=978-1-61132-324-5|location=Walnut Creek|pages=13–17|oclc=855969933}}</ref> It also occurred independently in [[Mesoamerica]] (about 6,000 years ago),<ref>{{cite book | vauthors = Scanes CG |date= January 2018 | chapter =The Neolithic Revolution, Animal Domestication, and Early Forms of Animal Agriculture | veditors = Scanes CG, Toukhsati SR |title = Animals and Human Society |pages=103–131 |doi=10.1016/B978-0-12-805247-1.00006-X|isbn= 9780128052471 }}</ref> China,<ref name="He2017">{{cite journal | vauthors = He K, Lu H, Zhang J, Wang C, Huan X |title=Prehistoric evolution of the dualistic structure mixed rice and millet farming in China |journal=The Holocene |date=7 June 2017 |volume=27 |issue=12 |pages=1885–1898 |doi=10.1177/0959683617708455 |bibcode=2017Holoc..27.1885H |s2cid=133660098 |url=https://www.researchgate.net/publication/317400332}}</ref><ref name="Lu">{{cite journal | vauthors = Lu H, Zhang J, Liu KB, Wu N, Li Y, Zhou K, Ye M, Zhang T, Zhang H, Yang X, Shen L, Xu D, Li Q | display-authors = 6 | title = Earliest domestication of common millet (Panicum miliaceum) in East Asia extended to 10,000 years ago | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 106 | issue = 18 | pages = 7367–72 | date = May 2009 | pmid = 19383791 | pmc = 2678631 | doi = 10.1073/pnas.0900158106 | bibcode = 2009PNAS..106.7367L | doi-access = free }}</ref> [[Papua New Guinea]],<ref>{{cite journal | vauthors = Denham TP, Haberle SG, Lentfer C, Fullagar R, Field J, Therin M, Porch N, Winsborough B | display-authors = 6 | title = Origins of agriculture at Kuk Swamp in the highlands of New Guinea | journal = Science | volume = 301 | issue = 5630 | pages = 189–93 | date = July 2003 | pmid = 12817084 | doi = 10.1126/science.1085255 | s2cid = 10644185 }}</ref> and the [[Sahel]] and [[Sudanian savanna|West Savanna]] regions of Africa.<ref>{{cite journal | vauthors = Scarcelli N, Cubry P, Akakpo R, Thuillet AC, Obidiegwu J, Baco MN, Otoo E, Sonké B, Dansi A, Djedatin G, Mariac C, Couderc M, Causse S, Alix K, Chaïr H, François O, Vigouroux Y | display-authors = 6 | title = Yam genomics supports West Africa as a major cradle of crop domestication | journal = Science Advances | volume = 5 | issue = 5 | pages = eaaw1947 | date = May 2019 | pmid = 31114806 | doi = 10.1126/sciadv.aaw1947 | pmc = 6527260 | bibcode = 2019SciA....5.1947S | doi-access = free }}</ref><ref>{{cite journal| vauthors = Winchell F |date=October 2017|title=Evidence for Sorghum Domestication in Fourth Millennium BC Eastern Sudan: Spikelet Morphology from Ceramic Impressions of the Butana Group|journal=Current Anthropology|volume=58|issue=5|pages=673–683|doi=10.1086/693898|s2cid=149402650|url=https://discovery.ucl.ac.uk/id/eprint/1574602/7/Fuller_693898.pdf}}</ref><ref>{{cite journal| vauthors = Manning K |date=February 2011|title=4500-Year old domesticated pearl millet (Pennisetum glaucum) from the Tilemsi Valley, Mali: new insights into an alternative cereal domestication pathway |journal=Journal of Archaeological Science|volume=38|issue=2|pages=312–322|doi=10.1016/j.jas.2010.09.007 }}</ref> Access to food surplus led to the formation of permanent [[human settlement]]s, the [[domestication]] of animals and the [[Chalcolithic|use of metal tools]] for the first time in history. Agriculture and sedentary lifestyle led to the emergence of early [[civilizations]].<ref>{{cite book| vauthors = Noble TF, Strauss B, Osheim D, Neuschel K, Accamp E |url=https://books.google.com/books?id=Td4WAAAAQBAJ&q=western%20civilisation%20egypt&pg=PA16|title=Cengage Advantage Books: Western Civilization: Beyond Boundaries|date=2013|isbn=978-1-285-66153-7|access-date=11 July 2015}}</ref><ref>{{cite book| vauthors = Spielvogel J |url=https://books.google.com/books?id=LceiAgAAQBAJ&q=western%20civilisation%20egypt&pg=PT65|title=Western Civilization: Volume A: To 1500|date=1 January 2014|publisher=Cenpage Learning|isbn=978-1-285-98299-1|access-date=11 July 2015|archive-url=https://web.archive.org/web/20150905105225/https://books.google.com/books?id=LceiAgAAQBAJ&pg=PT65#v=onepage&q=western%20civilisation%20egypt|archive-date=5 September 2015|url-status=live}}</ref><ref>{{cite book| vauthors = Thornton B |url=https://books.google.com/books?id=fa6swJv64xkC&q=Greek%20Ways%3A%20How%20the%20Greeks%20Created%20Western%20Civilization|title=Greek Ways: How the Greeks Created Western Civilization|publisher=Encounter Books|year=2002|isbn=978-1-893554-57-3|location=San Francisco, CA|pages=1–14}}</ref>

An [[urban revolution]] took place in the [[4th millennium BC|4th millennium BCE]] with the development of [[city-state]]s, particularly [[Sumer]]ian cities located in [[Mesopotamia]].<ref>{{cite book| vauthors = Garfinkle SJ, Bang PF, Scheidel W | veditors = Bang PF, Scheidel W |date=2013-02-01|title=Ancient Near Eastern City-States|url=https://www.oxfordhandbooks.com/view/10.1093/oxfordhb/9780195188318.001.0001/oxfordhb-9780195188318-e-4|access-date=2021-04-16|website=The Oxford Handbook of the State in the Ancient Near East and Mediterranean |language=en |doi=10.1093/oxfordhb/9780195188318.001.0001|isbn=9780195188318}}</ref> It was in these cities that the earliest known form of writing, [[cuneiform script]], appeared around 3000 BCE.<ref>{{cite book | vauthors = Woods C | chapter = The Emergence of Cuneiform Writing|date=2020-02-28 |title = A Companion to Ancient Near Eastern Languages|pages=27–46| veditors = Hasselbach-Andee R |edition=1st |publisher=Wiley|language=en|doi=10.1002/9781119193814.ch2|isbn=978-1-119-19329-6 | s2cid = 216180781}}</ref> Other major civilizations to develop around this time were [[Ancient Egypt]] and the [[Indus Valley civilisation|Indus Valley Civilization]].<ref>{{cite journal | vauthors = Robinson A | title = Ancient civilization: Cracking the Indus script | journal = Nature | volume = 526 | issue = 7574 | pages = 499–501 | date = October 2015 | pmid = 26490603 | doi = 10.1038/526499a | bibcode = 2015Natur.526..499R | s2cid = 4458743 }}</ref> They eventually traded with each other and invented technology such as wheels, plows and sails.<ref>{{cite book| vauthors = Crawford H |title=The Sumerian World|publisher=Routledge|year=2013|isbn=978-1-136-21911-5 |pages=447–61|chapter=Trade in the Sumerian world}}</ref><ref name=":14">{{cite journal| vauthors = Bodnár M |date=2018|title=Prehistoric innovations: Wheels and wheeled vehicles|url=https://www.ceeol.com/search/article-detail?id=714342|journal=Acta Archaeologica Academiae Scientiarum Hungaricae|language=English|volume=69|issue=2|pages=271–298|doi=10.1556/072.2018.69.2.3|s2cid=115685157|issn=0001-5210}}</ref><ref>{{cite journal| vauthors = Pryor FL |date=1985|title=The Invention of the Plow|url=https://www.jstor.org/stable/178600|journal=Comparative Studies in Society and History|volume=27|issue=4|pages=727–743|doi=10.1017/S0010417500011749|jstor=178600|s2cid=144840498|issn=0010-4175}}</ref><ref name="Carter">{{cite book|vauthors=Carter R |url=https://www.academia.edu/1576775|title=A companion to the archaeology of the ancient Near East|publisher=Wiley-Blackwell|year=2012|isbn=978-1-4051-8988-0|veditors=Potts DT |location=Chichester, West Sussex|pages=347–354|chapter=19. [[Watercraft]]|access-date=8 February 2014|archive-url=https://web.archive.org/web/20150428190743/https://www.academia.edu/1576775/Watercraft|archive-date=28 April 2015|url-status=live}}</ref> Astronomy and mathematics were also developed and the [[Great Pyramid of Giza]] was built.<ref>{{cite book| vauthors = Pedersen O |title=Early physics and astronomy: A historical introduction.|publisher=CUP Archive|year=1993|isbn=978-0-521-40340-5|page=1|chapter=Science Before the Greeks}}</ref><ref>{{cite book| vauthors = Robson E |title=Mathematics in ancient Iraq: A social history.|publisher=Princeton University Press|year=2008|pages=xxi}}</ref><ref>{{cite journal| vauthors = Edwards JF |date=2003|title=Building the Great Pyramid: Probable Construction Methods Employed at Giza|url=https://www.jstor.org/stable/25148110|journal=Technology and Culture|volume=44|issue=2|pages=340–354|doi=10.1353/tech.2003.0063|jstor=25148110|s2cid=109998651|issn=0040-165X}}</ref> There is evidence of a [[4.2-kiloyear event|severe drought]] lasting about a hundred years that may have caused the decline of these civilizations,<ref>{{cite journal | vauthors = Voosen P | title = New geological age comes under fire | journal = Science | volume = 361 | issue = 6402 | pages = 537–538 | date = August 2018 | pmid = 30093579 | doi = 10.1126/science.361.6402.537 | bibcode = 2018Sci...361..537V | s2cid = 51954326 }}</ref> with new ones appearing in the aftermath. [[Babylonia]]ns came to dominate Mesopotamia while others,<ref>{{cite book| vauthors = Saggs HW |title=Babylonians|publisher=Univ of California Press|year=2000|isbn=978-0-520-20222-1|page=7}}</ref> such as [[Poverty Point culture]]s, [[Minoan civilization|Minoans]] and the [[Shang dynasty]], rose to prominence in new areas.<ref>{{cite journal| vauthors = Sassaman KE |date=2005-12-01|title=Poverty Point as Structure, Event, Process |journal=Journal of Archaeological Method and Theory|language=en|volume=12|issue=4|pages=335–364|doi=10.1007/s10816-005-8460-4|s2cid=53393440|issn=1573-7764}}</ref><ref>{{cite journal | vauthors = Lazaridis I, Mittnik A, Patterson N, Mallick S, Rohland N, Pfrengle S, Furtwängler A, Peltzer A, Posth C, Vasilakis A, McGeorge PJ, Konsolaki-Yannopoulou E, Korres G, Martlew H, Michalodimitrakis M, Özsait M, Özsait N, Papathanasiou A, Richards M, Roodenberg SA, Tzedakis Y, Arnott R, Fernandes DM, Hughey JR, Lotakis DM, Navas PA, Maniatis Y, Stamatoyannopoulos JA, Stewardson K, Stockhammer P, Pinhasi R, Reich D, Krause J, Stamatoyannopoulos G | display-authors = 6 | title = Genetic origins of the Minoans and Mycenaeans | journal = Nature | volume = 548 | issue = 7666 | pages = 214–218 | date = August 2017 | pmid = 28783727 | doi = 10.1038/nature23310 | pmc = 5565772 | bibcode = 2017Natur.548..214L }}</ref><ref>{{cite book| vauthors = Keightley DN |title=The Cambridge History of Ancient China: From the Origins of Civilization to 221 BC |publisher=Cambridge University Press|year=1999|isbn=978-0-521-47030-8 | veditors = Loewe M, Shaughnessy EL |pages=232–291|chapter=The Shang: China's first historical dynasty}}</ref> The Bronze Age suddenly [[Late Bronze Age collapse|collapsed]] around 1200 BCE, resulting in the disappearance of a number of civilizations and the beginning of the [[Greek Dark Ages]].<ref>{{cite journal| vauthors = Kaniewski D, Guiot J, van Campo E |date=2015|title=Drought and societal collapse 3200 years ago in the Eastern Mediterranean: a review |journal=WIREs Climate Change |volume=6 |issue=4 |pages=369–382 |doi=10.1002/wcc.345 |s2cid=128460316}}</ref><ref>{{cite journal | vauthors = Drake BL |date=2012-06-01|title=The influence of climatic change on the Late Bronze Age Collapse and the Greek Dark Ages |journal=Journal of Archaeological Science |volume=39|issue=6|pages=1862–1870 |doi=10.1016/j.jas.2012.01.029 }}</ref> During this period iron started replacing bronze, leading to the [[Iron Age]].<ref>{{cite book | vauthors = Wells PS | chapter =The Iron Age|date=2011 | title = European Prehistory: A Survey|pages=405–460| veditors = Milisauskas S |series=Interdisciplinary Contributions to Archaeology|place=New York, NY|publisher=Springer|language=en|doi=10.1007/978-1-4419-6633-9_11|isbn=978-1-4419-6633-9 }}</ref>

In the 5th century BCE, history started being [[Historiography|recorded as a discipline]], which provided a much clearer picture of life at the time.<ref>{{cite book| vauthors = Hughes-Warrington M |title=History as Wonder: Beginning with Historiography.|publisher=Taylor & Francis|year=2018|isbn=978-0-429-76315-1 |location=United Kingdom|chapter=Sense and non-sense in Ancient Greek histories}}</ref> Between the 8th and 6th century BCE, Europe entered the [[classical antiquity]] age, a period when [[ancient Greece]] and [[ancient Rome]] flourished.<ref>{{cite web|date=2015-10-02| vauthors = Beard M | title = Why ancient Rome matters to the modern world|url=https://www.theguardian.com/books/2015/oct/02/mary-beard-why-ancient-rome-matters|access-date=2021-04-17|website=The Guardian|language=en}}</ref><ref>{{cite web| vauthors = Vidergar AB |date=2015-06-11|title=Stanford scholar debunks long-held beliefs about economic growth in ancient Greece|url=https://news.stanford.edu/news/2015/june/greek-economy-growth-061115.html|access-date=2021-04-17|website=Stanford University|language=en}}</ref> Around this time other civilizations also came to prominence. The [[Maya civilization]] started to build cities and create [[Maya calendar|complex calendars]].<ref>{{cite journal | vauthors = Inomata T, Triadan D, Vázquez López VA, Fernandez-Diaz JC, Omori T, Méndez Bauer MB, García Hernández M, Beach T, Cagnato C, Aoyama K, Nasu H | display-authors = 6 | title = Monumental architecture at Aguada Fénix and the rise of Maya civilization | journal = Nature | volume = 582 | issue = 7813 | pages = 530–533 | date = June 2020 | pmid = 32494009 | doi = 10.1038/s41586-020-2343-4 | bibcode = 2020Natur.582..530I | s2cid = 219281856 }}</ref><ref>{{cite journal| vauthors = Milbrath S |date=March 2017|title=The Role of Solar Observations in Developing the Preclassic Maya Calendar |url= https://www.cambridge.org/core/product/identifier/S1045663516000043/type/journal_article |journal=Latin American Antiquity|language=en|volume=28|issue=1|pages=88–104|doi=10.1017/laq.2016.4|s2cid=164417025|issn=1045-6635}}</ref> In Africa, the [[Kingdom of Aksum]] overtook the declining [[Kingdom of Kush]] and facilitated trade between India and the Mediterranean.<ref>{{cite journal| vauthors = Benoist A, Charbonnier J, Gajda I |date=2016|title=Investigating the eastern edge of the kingdom of Aksum: architecture and pottery from Wakarida|url=https://www.jstor.org/stable/45163415|journal=Proceedings of the Seminar for Arabian Studies|volume=46|pages=25–40|jstor=45163415|issn=0308-8421}}</ref> In West Asia, the [[Achaemenid Empire|Achaemenid Empire's]] system of centralized governance became the precursor to many later empires,<ref>{{cite journal| vauthors = Farazmand A |date=1998-01-01|title=Administration of the Persian achaemenid world-state empire: implications for modern public administration |journal=International Journal of Public Administration|volume=21|issue=1|pages=25–86|doi=10.1080/01900699808525297|issn=0190-0692}}</ref> while the [[Gupta Empire]] in India and the [[Han dynasty]] in China have been described as [[golden ages]] in their respective regions.<ref>{{cite journal| vauthors = Ingalls DH |date=1976|title=Kālidāsa and the Attitudes of the Golden Age|url=https://www.jstor.org/stable/599886|journal=Journal of the American Oriental Society|volume=96|issue=1|pages=15–26|doi=10.2307/599886|jstor=599886|issn=0003-0279}}</ref><ref>{{cite journal| vauthors = Xie J |date=2020|title=Pillars of Heaven: The Symbolic Function of Column and Bracket Sets in the Han Dynasty|url=https://www.cambridge.org/core/product/identifier/S0066622X20000015/type/journal_article|journal=Architectural History|language=en|volume=63|pages=1–36|doi=10.1017/arh.2020.1|s2cid=229716130|issn=0066-622X}}</ref>

Following the [[fall of the Western Roman Empire]] in 476, Europe entered the [[Middle Ages]].<ref>{{cite journal| vauthors = Marx W, Haunschild R, Bornmann L |date=2018|title=Climate and the Decline and Fall of the Western Roman Empire: A Bibliometric View on an Interdisciplinary Approach to Answer a Most Classic Historical Question|journal=Climate|language=en|volume=6|issue=4|page=90|doi=10.3390/cli6040090|doi-access=free}}</ref> During this period, [[Christianity]] and the [[Catholic Church|Church]] would become the source of centralized authority and education.<ref name="Oxford University Press">{{cite book| veditors = Brooke JH, Numbers RL |title=Science and Religion Around the World|date=2011|publisher=Oxford University Press|location=New York|isbn=978-0-195-32819-6|page=72|url=https://books.google.com/books?id=W6HPW1TodZwC&pg=PA71}}</ref> In the Middle East, [[Islam]] became the prominent religion and expanded into North Africa. It led to an [[Islamic Golden Age]], inspiring achievements in [[architecture]], the revival of old advances in science and technology, and the formation of a distinct way of life.<ref name=":15">{{cite book | vauthors = Renima A, Tiliouine H, Estes RJ | chapter = The Islamic Golden Age: A Story of the Triumph of the Islamic Civilization|date=2016 | title = The State of Social Progress of Islamic Societies: Social, Economic, Political, and Ideological Challenges|pages=25–52| veditors = Tiliouine H, Estes RJ |series=International Handbooks of Quality-of-Life|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-24774-8_2|isbn=978-3-319-24774-8 }}</ref><ref>{{Cite book|title=The Harper Atlas of World History| vauthors = Vidal-Nanquet P |publisher=Harper & Row Publishers|year=1987|page=76}}</ref> The [[Christendom|Christian]] and [[Islamic world]]s would eventually clash, with the [[Kingdom of England]], the [[Kingdom of France]] and the [[Holy Roman Empire]] declaring a series of [[crusades|holy wars]] to regain control of the [[Holy Land]] from [[Muslim]]s.<ref>{{cite book| vauthors = Asbridge T |title=The Crusades: The War for the Holy Land|publisher=Simon and Schuster|year=2012|isbn=978-1849837705|chapter=Introduction: The world of the crusades}}</ref> In the Americas, complex [[Mississippian culture|Mississippian societies]] would arise starting around 800 CE,<ref>{{Cite encyclopedia| url= https://www.georgiaencyclopedia.org/nge/Article.jsp?id=h-707 |author= Adam King|title= Mississippian Period: Overview| encyclopedia= New Georgia Encyclopedia| date= 2002| access-date = 15 Nov 2009}}</ref> while further south, the [[Aztecs]] and [[Incas]] would become the dominant powers.<ref>{{cite book| vauthors = Conrad G, Demarest AA |title=Religion and Empire: The Dynamics of Aztec and Inca Expansionism|publisher=Cambridge University Press|year=1984|isbn=0521318963|page=2}}</ref> The [[Mongol Empire]] would conquer much of [[Eurasia]] in the 13th and 14th centuries.<ref>{{cite book| vauthors = May T |title=The Mongol Conquests in World History| publisher=Reaktion Books |year=2013|isbn=978-1-86189-971-2 |page=7}}</ref> Over this same time period, the [[Mali Empire]] in Africa grew to be the largest empire on the continent, stretching from [[Senegambia]] to [[Ivory Coast]].<ref>{{Cite encyclopedia| vauthors = Canós-Donnay S |title=The Empire of Mali|date=2019-02-25|url= https://oxfordre.com/africanhistory/view/10.1093/acrefore/9780190277734.001.0001/acrefore-9780190277734-e-266|encyclopedia=Oxford Research Encyclopedia of African History|publisher=Oxford University Press|language=en|doi=10.1093/acrefore/9780190277734.013.266|isbn=978-0-19-027773-4|access-date=2021-05-07}}</ref> Oceania would see the rise of the [[Tuʻi Tonga Empire]] which expanded across many islands in the South Pacific.<ref>{{cite journal| vauthors = Canela SA, Graves MW |title=The Tongan Maritime Expansion: A Case in the Evolutionary Ecology of Social Complexity|journal=Asian Perspectives|volume=37|issue=2|pages=135–164|url=https://www.researchgate.net/publication/46734826}}</ref>

Throughout the [[early modern period]] (1500–1800), the [[Rise of the Ottoman Empire|Ottomans]] controlled the lands around the [[Mediterranean Basin]],<ref>{{cite book | chapter = Ottomans and Europe|date=1994-01-01| chapter-url=https://brill.com/view/book/edcoll/9789004391659/BP000019.xml|title = Handbook of European History 1400-1600: Late Middle Ages, Renaissance and Reformation|pages=589–635| veditors = Brady T, Oberman T, Tracy JD |publisher=Brill |doi=10.1163/9789004391659_019|isbn=978-90-04-39165-9|access-date=2021-04-17}}</ref> Japan entered the [[Edo period]],<ref>{{Cite encyclopedia| vauthors = Goree R |title=The Culture of Travel in Edo-Period Japan|date=2020-11-19|url=https://oxfordre.com/asianhistory/view/10.1093/acrefore/9780190277727.001.0001/acrefore-9780190277727-e-72|encyclopedia=Oxford Research Encyclopedia of Asian History|publisher=Oxford University Press|language=en|doi=10.1093/acrefore/9780190277727.013.72|isbn=978-0-19-027772-7|access-date=2021-05-07}}</ref> the [[Qing dynasty]] rose in China<ref>{{Cite journal| vauthors = Mosca MW |date=2010|title=CHINA'S LAST EMPIRE: The Great Qing|url=https://www.proquest.com/openview/a516602ac28aba8955507e46ab41483e/1?pq-origsite=gscholar&cbl=25135|journal=Pacific Affairs|volume=83}}</ref> and the [[Mughal Empire]] ruled much of India.<ref>{{Cite journal| vauthors = Suyanta S, Ikhlas S |date=2016-07-19|title=Islamic Education at Mughal Kingdom in India (1526-1857)|url=https://journal.tarbiyahiainib.ac.id/index.php/attalim/article/view/228|journal=Al-Ta Lim Journal|volume=23|issue=2|pages=128–138|doi=10.15548/jt.v23i2.228|issn=2355-7893}}</ref> Europe underwent the [[Renaissance]], starting in the 15th century,<ref>{{cite book| vauthors = Kirkpatrick R |url=https://www.worldcat.org/oclc/893909816|title=The European Renaissance, 1400-1600|date=2002|isbn=978-1-317-88646-4|location=Harlow, England|page=1|oclc=893909816}}</ref> and the [[Age of Discovery]] began with the exploring and [[Colonialism|colonizing]] of new regions.<ref>{{cite book| vauthors = Arnold D |url=https://www.worldcat.org/oclc/859536800|title=The Age of Discovery, 1400-1600|date=2002|isbn=978-1-136-47968-7|edition=Second|location=London|pages=xi|oclc=859536800}}</ref> This includes the [[British Empire]] expanding to become the [[Largest empire|world's largest empire]]<ref>{{cite journal| vauthors = Palan R |date=2010-01-14|title=International Financial Centers: The British-Empire, City-States and Commercially Oriented Politics|url=https://www.degruyter.com/document/doi/10.2202/1565-3404.1239/html|journal=Theoretical Inquiries in Law|volume=11|issue=1|doi=10.2202/1565-3404.1239|s2cid=56216309|issn=1565-3404}}</ref> and [[European colonization of the Americas|the colonization of the Americas]].<ref>{{cite journal| vauthors = Dixon EJ |date= January 2001 |title=Human colonization of the Americas: timing, technology and process |journal=Quaternary Science Reviews|language=en|volume=20|issue=1–3 |pages=277–299|doi=10.1016/S0277-3791(00)00116-5|bibcode= 2001QSRv...20..277J }}</ref> This expansion led to the [[Atlantic slave trade]]<ref>{{Cite journal| vauthors = Lovejoy PE |date=1989 |title=The Impact of the Atlantic Slave Trade on Africa: A Review of the Literature|url=https://www.jstor.org/stable/182914|journal=The Journal of African History |volume=30 |issue=3 |pages=365–394 |doi=10.1017/S0021853700024439 |jstor=182914|s2cid=161321949 |issn=0021-8537}}</ref> and the [[Genocide of indigenous peoples#Native American Genocide|genocide of Native American peoples]].<ref>{{cite book | vauthors = Cave AA | chapter = Genocide in the Americas|date=2008 | title = The Historiography of Genocide|pages=273–295 | veditors = Stone D |place=London|publisher=Palgrave Macmillan UK|language=en|doi=10.1057/9780230297784_11|isbn=978-0-230-29778-4}}</ref> This period also marked the [[Scientific Revolution]], with great advances in [[mathematics]], [[mechanics]], [[astronomy]] and [[physiology]].<ref>{{cite journal | vauthors = Delisle RG | title = Can a revolution hide another one? Charles Darwin and the Scientific Revolution | journal = Endeavour | volume = 38 | issue = 3–4 | pages = 157–8 | date = September 2014 | pmid = 25457642 | doi = 10.1016/j.endeavour.2014.10.001 }}</ref>

The [[late modern period]] (1800–present) saw the [[Technological Revolution|Technological]] and [[Industrial Revolution]] bring such discoveries as [[imaging technology]], major innovations in transport and [[energy development]].<ref>{{cite web|title=Greatest Engineering Achievements of the 20th Century|url=https://www.greatachievements.org/|url-status=live|archive-url=https://web.archive.org/web/20150406160644/https://greatachievements.org/|archive-date=6 April 2015|access-date=7 April 2015| work = National Academy of Engineering }}</ref> The [[United States|United States of America]] underwent great change, going from a small group of colonies to one of the [[global superpower]]s.<ref>{{Cite book| vauthors = Herring GC |url=https://www.worldcat.org/oclc/299054528|title=From colony to superpower : U.S. foreign relations since 1776|date=2008|publisher=Oxford University Press|isbn=978-0-19-972343-0|location=New York|page=1|oclc=299054528}}</ref> The [[Napoleonic Wars]] raged through Europe in the early 1800s,<ref>{{Cite journal| vauthors = O'Rourke KH | date=March 2006|title=The worldwide economic impact of the French Revolutionary and Napoleonic Wars, 1793–1815|url=https://www.cambridge.org/core/product/identifier/S1740022806000076/type/journal_article|journal=Journal of Global History|language=en|volume=1|issue=1|pages=123–149|doi=10.1017/S1740022806000076|issn=1740-0228}}</ref> Spain lost most of its [[New World]] colonies<ref>{{Cite journal| vauthors = Zimmerman AF |date=November 1931|title=Spain and Its Colonies, 1808-1820|url=https://www.jstor.org/stable/2506251|journal=The Hispanic American Historical Review|volume=11|issue=4|pages=439–463|doi=10.2307/2506251|jstor=2506251}}</ref> and Europeans continued expansion into Oceania<ref>{{Cite journal| vauthors = Raudzens G |date=2004|title=The Australian Frontier Wars, 1788-1838 (review)|url=https://dx.doi.org/10.1353/jmh.2004.0138|journal=The Journal of Military History|volume=68|issue=3|pages=957–959|doi=10.1353/jmh.2004.0138|s2cid=162259092|issn=1543-7795}}</ref> and [[Scramble for Africa|Africa]] (where European control went from 10% to almost 90% in less than 50 years).<ref>{{cite web| vauthors = David S |date=2011|title=British History in depth: Slavery and the 'Scramble for Africa' |url=https://www.bbc.co.uk/history/british/abolition/scramble_for_africa_article_01.shtml |access-date=2021-05-05|website=www.bbc.co.uk|language=en-GB}}</ref> A tenuous [[Balance of power (international relations)|balance of power]] among European nations collapsed in 1914 with the outbreak of the [[World War I|First World War]], one of the deadliest conflicts in history.<ref>{{Cite book| vauthors = Clark CM |url=https://www.worldcat.org/oclc/794136314|title=The sleepwalkers : how Europe went to war in 1914|date=2012|publisher=Allen Lane|isbn=978-0-7139-9942-6|location=London|chapter=Polarization of Europe, 1887-1907|oclc=794136314}}</ref> In the 1930s, a [[Great Depression|worldwide economic crisis]] led to the rise of [[authoritarian]] regimes and a [[World War II|Second World War]], involving [[World War II by country|almost all the world's countries]].<ref>{{cite book |author=Robert Dahl |title=Democracy and Its Critics |url=https://archive.org/details/democracyitscrit00dahl_0 |url-access=registration |year=1989 |publisher=Yale UP |pages=[https://archive.org/details/democracyitscrit00dahl_0/page/239 239–40] |isbn=0300153554}}</ref> Following its conclusion in 1945, the [[Cold War]] between the [[USSR]] and the United States saw a struggle for global influence, including a [[nuclear arms race]] and a [[Space Race|space race]].<ref>{{Cite journal| vauthors = McDougall WA |date=May 1985|title=Sputnik, the space race, and the Cold War|url=https://www.tandfonline.com/doi/full/10.1080/00963402.1985.11455962|journal=Bulletin of the Atomic Scientists|language=en|volume=41|issue=5|pages=20–25|doi=10.1080/00963402.1985.11455962|bibcode=1985BuAtS..41e..20M|issn=0096-3402}}</ref><ref>{{Cite journal| vauthors = Plous S |date=May 1993|title=The Nuclear Arms Race: Prisoner's Dilemma or Perceptual Dilemma?|url=https://journals.sagepub.com/doi/10.1177/0022343393030002004|journal=Journal of Peace Research|language=en|volume=30|issue=2|pages=163–179|doi=10.1177/0022343393030002004|s2cid=5482851|issn=0022-3433}}</ref> The current [[Information Age]] sees the world becoming increasingly [[Globalization|globalized]] and interconnected.<ref>{{Cite journal| vauthors = Sachs JD |date=April 2017|title=Globalization—In the Name of Which Freedom?|url=https://link.springer.com/10.1007/s41463-017-0019-5|journal=Humanistic Management Journal|language=en|volume=1|issue=2|pages=237–252|doi=10.1007/s41463-017-0019-5|s2cid=133030709|issn=2366-603X}}</ref>

== Habitat and population ==

| image            = [[File:World Population.svg|300px]]

| caption          = {{hlist|{{Legend inline|#000000|1,000+ million}}|{{Legend inline|#171b59|200–1,000 million}}|{{Legend inline|#212680|100–200 million}}|{{Legend inline|#3239bf|75–100 million}}|{{Legend inline|#424cff|50–75 million}}|{{Legend inline|#5c64ff|25–50 million}}|{{Legend inline|#757cff|10–25 million}}|{{Legend inline|#8f94ff|5–10 million}}|{{Legend inline|#a8adff|&lt;5 million}} }}

| title            = Population statistics{{#tag:ref|The world population and population density statistics are updated automatically from a template that uses the CIA World Factbook and United Nations World Population Prospects.<ref>{{cite web| url=https://www.cia.gov/the-world-factbook/countries/world |title=World |work=[[The World Factbook]] |publisher=[[CIA]] |date=17 May 2016 |access-date=2 October 2016}}</ref><ref>{{cite web |url=https://esa.un.org/unpd/wpp/Publications/Files/WPP2017_KeyFindings.pdf |publisher=United Nations, Department of Economic and Social Affairs, Population Division |date=2017 |title= World Population Prospects: The 2017 Revision|page=2&17}}</ref>|group=n}}

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In general, humans can survive for up to eight weeks without food, depending on stored body fat.<ref>{{cite web| vauthors = Lieberson AD |date=2004|title=How Long Can a Person Survive without Food?|url=https://www.scientificamerican.com/article/how-long-can-a-person-survive-without-food/|access-date=2021-04-18|website=Scientific American|language=en}}</ref> Survival without water is usually limited to three or four days, with a maximum of one week.<ref>{{cite web| vauthors = Spector D |date=2018-03-09|title=Here's how many days a person can survive without water|url=https://www.businessinsider.com.au/how-many-days-can-you-survive-without-water-2014-5|access-date=2021-04-18|website=Business Insider Australia|language=en}}</ref> In 2020 it is estimated 9 million humans die every year from causes directly or indirectly related to [[starvation]].<ref>{{cite web| vauthors = Holmes J |title=Losing 25,000 to Hunger Every Day|url=https://www.un.org/en/chronicle/article/losing-25000-hunger-every-day|access-date=2021-04-18|website=United Nations|language=en}}</ref><ref>{{cite web| vauthors = Mai HJ |date=2020|title=U.N. Warns Number Of People Starving To Death Could Double Amid Pandemic|url=https://www.npr.org/sections/coronavirus-live-updates/2020/05/05/850470436/u-n-warns-number-of-people-starving-to-death-could-double-amid-pandemic|access-date=2021-04-18|website=NPR.org|language=en}}</ref> Childhood malnutrition is also common and contributes to the [[Disease burden|global burden of disease]].<ref>{{cite journal | vauthors = Murray CJ, Lopez AD | title = Global mortality, disability, and the contribution of risk factors: Global Burden of Disease Study | journal = Lancet | volume = 349 | issue = 9063 | pages = 1436–42 | date = May 1997 | pmid = 9164317 | doi = 10.1016/S0140-6736(96)07495-8 | s2cid = 2569153 }}</ref> However, global food distribution is not even, and [[obesity]] among some human populations has increased rapidly, leading to health complications and increased mortality in some [[developed country|developed]] and a few [[developing countries]]. Worldwide, over one billion people are obese,<ref name=Haslam>{{cite journal | vauthors = Haslam DW, James WP | title = Obesity | journal = Lancet | volume = 366 | issue = 9492 | pages = 1197–209 | date = October 2005 | pmid = 16198769 | doi = 10.1016/S0140-6736(05)67483-1 | s2cid = 208791491 }}</ref> while in the United States 35% of people are obese, leading to this being described as an "[[Epidemiology of obesity|obesity epidemic]]."<ref name=Catenacci>{{cite journal | vauthors = Catenacci VA, Hill JO, Wyatt HR | title = The obesity epidemic | journal = Clinics in Chest Medicine | volume = 30 | issue = 3 | pages = 415–44, vii | date = September 2009 | pmid = 19700042 | doi = 10.1016/j.ccm.2009.05.001 }}</ref> Obesity is caused by consuming more [[calorie]]s than are expended, so excessive weight gain is usually caused by an energy-dense diet.<ref name=Haslam/>

===Biological variation===

{{Main|Human genetic variation}}

[[File:Genetic Variation.jpg|upright=1.3|thumb|Changes in the number and order of genes (A-D) create genetic diversity within and between population]]

There is biological variation in the human species—with traits such as [[blood type]], [[genetic diseases]], [[Human skull|cranial features]], [[Human face|facial features]], [[organ systems]], [[eye color]], [[hair color]] and [[hair texture|texture]], [[Human height|height]] and [[Body shape|build]], and [[Human skin color|skin color]] varying across the globe. The typical height of an adult human is between {{Convert|1.4|and|1.9|m|ftin|abbr=on}}, although this varies significantly depending on sex, [[ethnic origin]], and family bloodlines.<ref>{{cite journal | vauthors = de Beer H | title = Observations on the history of Dutch physical stature from the late-Middle Ages to the present | journal = Economics and Human Biology | volume = 2 | issue = 1 | pages = 45–55 | date = March 2004 | pmid = 15463992 | doi = 10.1016/j.ehb.2003.11.001 }}</ref><ref name="adapt2">{{cite web | vauthors = O'Neil D |title=Adapting to Climate Extremes |url=https://anthro.palomar.edu/adapt/adapt_2.htm |work=Human Biological Adaptability |publisher=Palomar College |access-date=6 January 2013 |url-status=live |archive-url= https://web.archive.org/web/20130106211840/https://anthro.palomar.edu/adapt/adapt_2.htm |archive-date=6 January 2013 }}</ref> Body size is partly determined by genes and is also significantly influenced by environmental factors such as [[diet (nutrition)|diet]], exercise, and [[sleep pattern]]s.<ref>{{cite journal | vauthors = Rask-Andersen M, Karlsson T, Ek WE, Johansson Å | title = Gene-environment interaction study for BMI reveals interactions between genetic factors and physical activity, alcohol consumption and socioeconomic status | journal = PLOS Genetics | volume = 13 | issue = 9 | pages = e1006977 | date = September 2017 | pmid = 28873402 | pmc = 5600404 | doi = 10.1371/journal.pgen.1006977 }}</ref>

There is evidence that populations have adapted genetically to various external factors. The genes that allow adult humans to [[Lactose tolerance|digest lactose]] are present in high frequencies in populations that have long histories of cattle domestication and are more dependent on [[cow milk]].<ref>{{cite journal | vauthors = Beja-Pereira A, Luikart G, England PR, Bradley DG, Jann OC, Bertorelle G, Chamberlain AT, Nunes TP, Metodiev S, Ferrand N, Erhardt G | display-authors = 6 | title = Gene-culture coevolution between cattle milk protein genes and human lactase genes | journal = Nature Genetics | volume = 35 | issue = 4 | pages = 311–3 | date = December 2003 | pmid = 14634648 | doi = 10.1038/ng1263 | s2cid = 20415396 }}</ref> [[Sickle cell anemia]], which may provide increased resistance to [[malaria]], is frequent in populations where [[malaria]] is endemic.<ref name="Hedrick 2011">{{cite journal | vauthors = Hedrick PW | title = Population genetics of malaria resistance in humans | journal = Heredity | volume = 107 | issue = 4 | pages = 283–304 | date = October 2011 | pmid = 21427751 | pmc = 3182497 | doi = 10.1038/hdy.2011.16 }}</ref><ref name="Weatherall 2008">{{cite journal | vauthors = Weatherall DJ | title = Genetic variation and susceptibility to infection: the red cell and malaria | journal = British Journal of Haematology | volume = 141 | issue = 3 | pages = 276–86 | date = May 2008 | pmid = 18410566 | doi = 10.1111/j.1365-2141.2008.07085.x | s2cid = 28191911 | doi-access = free }}</ref> Populations that have for a very long time inhabited specific climates tend to have developed specific [[phenotype]]s that are beneficial for those environments—[[Allen's rule|short stature and stocky build in cold regions]], tall and lanky in hot regions, and with high lung capacities or other [[High-altitude adaptation in humans|adaptations at high altitudes]].<ref>{{cite journal| vauthors = Shelomi M, Zeuss D |date=2017-04-05|title=Bergmann's and Allen's Rules in Native European and Mediterranean Phasmatodea |journal=Frontiers in Ecology and Evolution|volume=5|doi=10.3389/fevo.2017.00025|s2cid=34882477|issn=2296-701X|doi-access=free}}</ref><ref>{{cite journal | vauthors = Panesar NS | title = Why are the high altitude inhabitants like the Tibetans shorter and lighter? | journal = Medical Hypotheses | volume = 71 | issue = 3 | pages = 453–6 | date = September 2008 | pmid = 18495367 | doi = 10.1016/j.mehy.2008.04.005 }}</ref> Some populations have evolved highly unique adaptations to very specific environmental conditions, such as those advantageous to ocean-dwelling lifestyles and [[freediving]] in the [[Bajau]].<ref name="Ilardo2018">{{cite journal | vauthors = Ilardo MA, Moltke I, Korneliussen TS, Cheng J, Stern AJ, Racimo F, de Barros Damgaard P, Sikora M, Seguin-Orlando A, Rasmussen S, van den Munckhof IC, Ter Horst R, Joosten LA, Netea MG, Salingkat S, Nielsen R, Willerslev E | display-authors = 6 | title = Physiological and Genetic Adaptations to Diving in Sea Nomads | journal = Cell | volume = 173 | issue = 3 | pages = 569–580.e15 | date = April 2018 | pmid = 29677510 | doi = 10.1016/j.cell.2018.03.054 | doi-access = free }}</ref>

Human hair ranges in color from [[Red hair|red]] to [[blond]] to [[Brown hair|brown]] to [[Black hair|black]], which is the most frequent.<ref>{{cite journal|vauthors=Rogers AR , Iltis D, Wooding S|year=2004|title=Genetic variation at the MC1R locus and the time since loss of human body hair|journal=Current Anthropology|volume=45|issue=1|pages=105–08|doi=10.1086/381006|s2cid=224795768}}</ref> Hair color depends on the amount of [[melanin]], with concentrations fading with increased age, leading to [[Grey hair|grey]] or even white hair. Skin color can range from [[Dark skin|darkest brown]] to [[Light skin|lightest peach]], or even nearly white or colorless in cases of [[albinism]].<ref name="roberts1">{{cite book| vauthors = Roberts D |title=Fatal Invention|publisher=The New Press|year=2011|location=London, New York}}</ref> It tends to vary [[Clinal variation|clinally]] and generally correlates with the level of ultraviolet radiation in a particular geographic area, with darker skin mostly around the equator.<ref name="jabl04">{{cite journal|vauthors=Nina J|year=2004|title=The evolution of human skin and skin color|journal=Annual Review of Anthropology|volume=33|pages=585–623|doi=10.1146/annurev.anthro.33.070203.143955}}</ref> Skin darkening may have evolved as protection against ultraviolet solar radiation.<ref>{{cite journal | vauthors = Jablonski NG, Chaplin G | title = Colloquium paper: human skin pigmentation as an adaptation to UV radiation | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 107 | issue = Supplement_2 | pages = 8962–8 | date = May 2010 | pmid = 20445093 | pmc = 3024016 | doi = 10.1073/pnas.0914628107 | bibcode = 2010PNAS..107.8962J | doi-access = free }}</ref> Light skin pigmentation protects against depletion of [[vitamin D]], which requires [[sunlight]] to make.<ref>{{cite journal | vauthors = Jablonski NG, Chaplin G | title = The evolution of human skin coloration | journal = Journal of Human Evolution | volume = 39 | issue = 1 | pages = 57–106 | date = July 2000 | pmid = 10896812 | doi = 10.1006/jhev.2000.0403 | url = https://www.bgsu.edu/departments/chem/faculty/leontis/chem447/PDF_files/Jablonski_skin_color_2000.pdf | archive-url = https://web.archive.org/web/20120114203210/https://www.bgsu.edu/departments/chem/faculty/leontis/chem447/PDF_files/Jablonski_skin_color_2000.pdf | archive-date = 14 January 2012 }}</ref> Human skin also has a capacity to darken (tan) in response to exposure to ultraviolet radiation.<ref>{{cite journal | vauthors = Harding RM, Healy E, Ray AJ, Ellis NS, Flanagan N, Todd C, Dixon C, Sajantila A, Jackson IJ, Birch-Machin MA, Rees JL | display-authors = 6 | title = Evidence for variable selective pressures at MC1R | journal = American Journal of Human Genetics | volume = 66 | issue = 4 | pages = 1351–61 | date = April 2000 | pmid = 10733465 | pmc = 1288200 | doi = 10.1086/302863 }}</ref><ref>{{cite book | vauthors = Robin A | date = 1991 | title = Biological Perspectives on Human Pigmentation | location = Cambridge | publisher = Cambridge University Press }}</ref>[[File:Seti1a.jpg|thumb|A [[Berbers|Libyan]], a [[Nubians|Nubian]], a [[Syrian people|Syrian]], and an [[Egyptians|Egyptian]], drawing by an unknown artist after a mural of the tomb of [[Seti I]].]]

There is relatively little variation between human geographical populations, and most of the variation that occurs is at the individual level.<ref name="roberts1" /><ref name="hgp">{{cite web|title=The Science Behind the Human Genome Project|url=https://www.ornl.gov/sci/techresources/Human_Genome/project/info.shtml|url-status=dead|archive-url=https://web.archive.org/web/20130102065343/https://www.ornl.gov/sci/techresources/Human_Genome/project/info.shtml|archive-date=2 January 2013|access-date=6 January 2013|work=Human Genome Project|publisher=US Department of Energy|quote=Almost all (99.9%) nucleotide bases are exactly the same in all people.}}</ref><ref name="enr1">{{cite web| vauthors = O'Neil D | title=Ethnicity and Race: Overview|url=https://anthro.palomar.edu/ethnicity/ethnic_1.htm#return_from_ethnic_identity_question|url-status=live|archive-url=https://web.archive.org/web/20130106212622/https://anthro.palomar.edu/ethnicity/ethnic_1.htm#return_from_ethnic_identity_question|archive-date=6 January 2013|access-date=6 January 2013|publisher=Palomar College}}</ref> Much of human variation is continuous, often with no clear points of demarcation.<ref name="pmid15507998">{{cite journal | vauthors = Keita SO, Kittles RA, Royal CD, Bonney GE, Furbert-Harris P, Dunston GM, Rotimi CN | title = Conceptualizing human variation | journal = Nature Genetics | volume = 36 | issue = 11 Suppl | pages = S17-20 | date = November 2004 | pmid = 15507998 | doi = 10.1038/ng1455 | doi-access = free }}</ref><ref name="vary02">{{cite web|title=Models of Classification|url=https://anthro.palomar.edu/vary/vary_2.htm|url-status=dead|archive-url=https://web.archive.org/web/20130106212400/https://anthro.palomar.edu/vary/vary_2.htm|archive-date=6 January 2013|access-date=6 January 2013|work=Modern Human Variation|publisher=Palomar College|vauthors=O'Neil D}}</ref><ref>{{cite journal|vauthors=Jablonski N|year=2004|title=The evolution of human skin and skin color|journal=Annual Review of Anthropology|volume=33|pages=585–623|doi=10.1146/annurev.anthro.33.070203.143955}}</ref><ref name="Palmie2007">{{cite journal|vauthors=Palmié S|date=May 2007|title=Genomics, divination, 'racecraft'|journal=American Ethnologist|volume=34|issue=2|pages=205–22|doi=10.1525/ae.2007.34.2.205}}</ref> Genetic data shows that no matter how population groups are defined, two people from the same population group are almost as different from each other as two people from any two different population groups.<ref>{{cite web|title=Genetic – Understanding Human Genetic Variation|url=https://science.education.nih.gov/supplements/nih1/genetic/guide/genetic_variation1.htm|url-status=dead|archive-url=https://web.archive.org/web/20130825143543/https://science.education.nih.gov/supplements/nih1/genetic/guide/genetic_variation1.htm|archive-date=25 August 2013|access-date=13 December 2013|work=Human Genetic Variation|publisher=National Institute of Health (NIH)|quote=In fact, research results consistently demonstrate that about 85 percent of all human genetic variation exists within human populations, whereas about only 15 percent of variation exists between populations.}}</ref><ref name="goodman1">{{cite web| vauthors = Goodman A |title=Interview with Alan Goodman|url=https://www.pbs.org/race/000_About/002_04-background-01-07.htm|url-status=live|archive-url=https://web.archive.org/web/20121029063805/https://www.pbs.org/race/000_About/002_04-background-01-07.htm|archive-date=29 October 2012|access-date=6 January 2013|work=Race Power of and Illusion|publisher=PBS}}</ref><ref>{{cite book| vauthors = Marks J |year=2010|chapter=Ten facts about human variation |title=Human Evolutionary Biology| veditors = Muehlenbein M |location=New York|publisher=Cambridge University Press|url=https://personal.uncc.edu/jmarks/pubs/tenfacts.pdf|url-status=dead|archive-url=https://web.archive.org/web/20120415012646/https://personal.uncc.edu/jmarks/pubs/tenfacts.pdf|archive-date=15 April 2012|access-date=5 September 2013}}</ref> Dark-skinned populations that are found in Africa, Australia, and South Asia are not closely related to each other.<ref name="jablo04">{{cite journal|vauthors=Nina J|year=2004|title=The evolution of human skin and skin color|journal=Annual Review of Anthropology|volume=33|pages=585–623|doi=10.1146/annurev.anthro.33.070203.143955|quote=genetic evidence [demonstrate] that strong levels of natural selection acted about 1.2 mya to produce darkly pigmented skin in early members of the genus Homo}}</ref><ref>{{cite web|title=Overview|url=https://anthro.palomar.edu/vary/vary_1.htm|url-status=dead|archive-url=https://web.archive.org/web/20121105101522/https://anthro.palomar.edu/vary/vary_1.htm|archive-date=5 November 2012|access-date=6 January 2013|work=Modern Human Variation|publisher=Palomar College|vauthors=O'Neil D}}</ref>

Genetic research has demonstrated that human populations native to the [[African continent]] are the most genetically diverse<ref name="Jorde2000">{{cite journal | vauthors = Jorde LB, Watkins WS, Bamshad MJ, Dixon ME, Ricker CE, Seielstad MT, Batzer MA | title = The distribution of human genetic diversity: a comparison of mitochondrial, autosomal, and Y-chromosome data | journal = American Journal of Human Genetics | volume = 66 | issue = 3 | pages = 979–88 | date = March 2000 | pmid = 10712212 | pmc = 1288178 | doi = 10.1086/302825 }}</ref> and genetic diversity decreases with migratory distance from Africa, possibly the result of [[Evolutionary bottleneck|bottlenecks]] during human migration.<ref name="sciencedaily.com">

{{cite web |date=19 July 2007 |title=New Research Proves Single Origin Of Humans In Africa |url=https://www.sciencedaily.com/releases/2007/07/070718140829.htm |website=[[Science Daily]] |access-date=5 September 2011 |url-status=live |archive-url=https://web.archive.org/web/20111104103559/https://www.sciencedaily.com/releases/2007/07/070718140829.htm |archive-date=4 November 2011 }}</ref><ref>{{cite journal | vauthors = Manica A, Amos W, Balloux F, Hanihara T | title = The effect of ancient population bottlenecks on human phenotypic variation | journal = Nature | volume = 448 | issue = 7151 | pages = 346–348 | date = July 2007 | pmid = 17637668 | pmc = 1978547 | doi = 10.1038/nature05951 | author-link3 = Francois Balloux | bibcode = 2007Natur.448..346M }}</ref> These non-African populations acquired new genetic inputs from local [[Interbreeding between archaic and modern humans|admixture with archaic populations]] and have much greater variation from [[Neanderthals]] and [[Denisovans]] than is found in Africa,<ref name="Bergstrom2020">{{cite journal | vauthors = Bergström A, McCarthy SA, Hui R, Almarri MA, Ayub Q, Danecek P, Chen Y, Felkel S, Hallast P, Kamm J, Blanché H, Deleuze JF, Cann H, Mallick S, Reich D, Sandhu MS, Skoglund P, Scally A, Xue Y, Durbin R, Tyler-Smith C | display-authors = 6 | title = Insights into human genetic variation and population history from 929 diverse genomes | journal = Science | volume = 367 | issue = 6484 | pages = eaay5012 | date = March 2020 | pmid = 32193295 | pmc = 7115999 | doi = 10.1126/science.aay5012 }} "Populations in central and southern Africa, the Americas, and Oceania each harbor tens to hundreds of thousands of ''private'', common genetic variants. Most of these variants arose as new mutations rather than through archaic introgression, except in Oceanian populations, where many private variants derive from Denisovan admixture."</ref> though Neanderthal admixture into African populations may be underestimated.<ref name="pmid32004458">{{cite journal | vauthors = Chen L, Wolf AB, Fu W, Li L, Akey JM | title = Identifying and Interpreting Apparent Neanderthal Ancestry in African Individuals | journal = Cell | volume = 180 | issue = 4 | pages = 677–687.e16 | date = February 2020 | pmid = 32004458 | pmc =  | doi = 10.1016/j.cell.2020.01.012 | s2cid = 210955842 }}</ref> Furthermore, recent studies have found that populations in [[sub-Saharan Africa]], and particularly [[West Africa]], have ancestral genetic variation which predates modern humans and has been lost in most non-African populations. Some of this ancestry is thought to originate from admixture with an [[Interbreeding between archaic and modern humans#Archaic African hominins|unknown archaic hominin]] that diverged before the split of Neanderthals and modern humans.<ref name="Bergstrom2020a">{{cite journal | vauthors = Bergström A, McCarthy SA, Hui R, Almarri MA, Ayub Q, Danecek P, Chen Y, Felkel S, Hallast P, Kamm J, Blanché H, Deleuze JF, Cann H, Mallick S, Reich D, Sandhu MS, Skoglund P, Scally A, Xue Y, Durbin R, Tyler-Smith C | display-authors = 6 | title = Insights into human genetic variation and population history from 929 diverse genomes | journal = Science | volume = 367 | issue = 6484 | pages = eaay5012 | date = March 2020 | pmid = 32193295 | pmc = 7115999 | doi = 10.1126/science.aay5012 }} "An analysis of archaic sequences in modern populations identifies ancestral genetic variation in African populations that likely predates modern humans and has been lost in most non-African populations."</ref><ref name="Durvasula2020">{{cite journal | vauthors = Durvasula A, Sankararaman S | title = Recovering signals of ghost archaic introgression in African populations | journal = Science Advances | volume = 6 | issue = 7 | pages = eaax5097 | date = February 2020 | pmid = 32095519 | pmc = 7015685 | doi = 10.1126/sciadv.aax5097 | bibcode = 2020SciA....6.5097D }} "Our analyses of site frequency spectra indicate that these populations derive 2 to 19% of their genetic ancestry from an archaic population that diverged before the split of Neanderthals and modern humans."</ref>

Humans are a [[Gonochorism|gonochoric]] species, meaning they are divided into male and female [[sex]]es.<ref>{{Cite book|url=https://books.google.com/books?id=z4pXRaZAkdkC&q=humans+are+dioecious+genetics&pg=PA75|title=Genetics: A Conceptual Approach|vauthors=Pierce BA|date=2012|publisher=Macmillan|isbn=978-1-4292-3252-4|pages=75|language=en}}</ref><ref>{{Cite book| vauthors = Muehlenbein MP |url=https://books.google.com/books?id=1VXX1jkhPH8C&q=humans+are+dioecious+biology&pg=PT57|title=Human Evolutionary Biology|date=2010-07-29|publisher=Cambridge University Press|isbn=978-0-521-87948-4| veditors = Jones J |page=74|language=en}}</ref><ref>{{Cite book| vauthors = Fusco G, Minelli A |url=https://books.google.com/books?id=AKGsDwAAQBAJ&q=homo+sapiens+gonochoric&pg=PA304|title=The Biology of Reproduction|date=2019-10-10|publisher=Cambridge University Press|isbn=978-1-108-49985-9|page=304|language=en}}</ref> The greatest degree of genetic [[Sex differences in humans|variation exists between males and females]]. While the [[nucleotide diversity|nucleotide]] genetic variation of individuals of the same sex across global populations is no greater than 0.1%–0.5%, the genetic difference between [[Man|males]] and [[woman|females]] is between 1% and 2%. Males on average are 15% heavier and {{Convert|15|cm|in|abbr=on|lk=off|0}} taller than females.<ref name="Gustafsson">{{cite journal | vauthors = Gustafsson A, Lindenfors P | title = Human size evolution: no evolutionary allometric relationship between male and female stature | journal = Journal of Human Evolution | volume = 47 | issue = 4 | pages = 253–66 | date = October 2004 | pmid = 15454336 | doi = 10.1016/j.jhevol.2004.07.004 }}</ref><ref name="NHANES_III_data">{{cite journal | vauthors = Ogden CL, Fryar CD, Carroll MD, Flegal KM | title = Mean body weight, height, and body mass index, United States 1960-2002 | journal = Advance Data | volume = | issue = 347 | pages = 1–17 | date = October 2004 | pmid = 15544194 | doi = | url = https://www.cdc.gov/nchs/data/ad/ad347.pdf | archive-url = https://archive.wikiwix.com/cache/20110223153209/https://www.cdc.gov/nchs/data/ad/ad347.pdf |archive-date=23 February 2011 }}</ref> On average, men have about 40–50% more upper body strength and 20–30% more lower body strength than women at the same weight, due to higher amounts of muscle and larger muscle fibers.<ref>{{cite journal | vauthors = Miller AE, MacDougall JD, Tarnopolsky MA, Sale DG | title = Gender differences in strength and muscle fiber characteristics | journal = European Journal of Applied Physiology and Occupational Physiology | volume = 66 | issue = 3 | pages = 254–62 | year = 1993 | pmid = 8477683 | doi = 10.1007/BF00235103 | hdl-access = free | s2cid = 206772211 | hdl = 11375/22586 }}</ref> Women generally have a higher [[body fat]] percentage than men.<ref>{{Cite book | vauthors = Bredella MA |chapter=Sex Differences in Body Composition|date=2017 |title=Sex and Gender Factors Affecting Metabolic Homeostasis, Diabetes and Obesity |series=Advances in Experimental Medicine and Biology|volume=1043 |pages=9–27| veditors = Mauvais-Jarvis F |place=Cham |publisher=Springer International Publishing |doi=10.1007/978-3-319-70178-3_2 |pmid=29224088|isbn=978-3-319-70177-6 }}</ref> Women have [[Human skin color#Sexual dimorphism|lighter skin]] than men of the same population; this has been explained by a higher need for vitamin D in females during pregnancy and [[lactation]].<ref>{{cite journal | vauthors = Rahrovan S, Fanian F, Mehryan P, Humbert P, Firooz A | title = Male versus female skin: What dermatologists and cosmeticians should know | journal = International Journal of Women's Dermatology | volume = 4 | issue = 3 | pages = 122–130 | date = September 2018 | pmid = 30175213 | pmc = 6116811 | doi = 10.1016/j.ijwd.2018.03.002 }}</ref> As there are chromosomal differences between females and males, some X and Y chromosome-related conditions and [[Disease|disorders]] only affect either men or women.<ref>{{cite web| vauthors = Easter C |title=Sex Linked|url=https://www.genome.gov/genetics-glossary/Sex-Linked|access-date=2021-04-18|website=National Human Genome Research Institute|language=en}}</ref> After allowing for body weight and volume, the male voice is usually an [[octave]] deeper than the female voice.<ref>{{cite journal | vauthors = Puts DA, Gaulin SJ, Verdolini K | title = Dominance and the evolution of sexual dimorphism in human voice pitch. | journal = Evolution and Human Behavior | date = July 2006 | volume = 27 | issue = 4 | pages = 283–96 | doi = 10.1016/j.evolhumbehav.2005.11.003 }}</ref> Women have a [[Sex differences in longevity|longer life span]] in almost every population around the world.<ref name="WHO">{{cite web | url = https://www.who.int/gender/documents/en/ | title = Gender, women, and health | archive-url = https://web.archive.org/web/20130625083240/https://www.who.int/gender/documents/en/ | archive-date=25 June 2013 | work = Reports from WHO 2002–2005 }}</ref>

==Psychology==

{{Main|Psychology}}[[File:NIA human brain drawing.jpg|thumb|Drawing of the [[human brain]], showing several important structures]]

The [[human brain]], the focal point of the [[central nervous system]] in humans, controls the [[peripheral nervous system]]. In addition to controlling "lower," involuntary, or primarily [[autonomic nervous system|autonomic]] activities such as [[respiration (physiology)|respiration]] and [[digestion]], it is also the locus of "higher" order functioning such as [[thought]], [[reason]]ing, and [[abstraction]].<ref>{{cite web | url = https://www.pbs.org/wnet/brain/3d/index.html | title = 3-D Brain Anatomy | archive-url = https://web.archive.org/web/20170905064816/https://www.pbs.org/wnet/brain/3d/index.html | archive-date=5 September 2017 | work = The Secret Life of the Brain | publisher = Public Broadcasting Service | access-date = 3 April 2005 }}</ref> These [[mental function|cognitive processes]] constitute the [[mind]], and, along with their [[behavior]]al consequences, are studied in the field of [[psychology]].

Humans have a larger and more developed [[prefrontal cortex]] than other primates, the region of the brain associated with higher [[cognition]].<ref>{{cite journal| vauthors = Stern P |date=2018-06-22|title=The human prefrontal cortex is special|url=https://www.science.org/doi/10.1126/science.2018.360.6395.twil|journal=Science|language=en|volume=360|issue=6395|pages=1311–1312|doi=10.1126/science.360.6395.1311-g|bibcode=2018Sci...360S1311S|s2cid=149581944|issn=0036-8075}}</ref> This has led humans to proclaim themselves to be more [[intelligence|intelligent]] than any other known species.<ref>{{cite journal| vauthors = Erickson R |date=2014-09-22|title=Are Humans the Most Intelligent Species?|journal=Journal of Intelligence|language=en|volume=2|issue=3|pages=119–121|doi=10.3390/jintelligence2030119|issn=2079-3200|doi-access=free}}</ref> Objectively defining intelligence is difficult, with other animals adapting senses and excelling in areas that humans are unable to.<ref>{{cite web|title=Humans not smarter than animals, just different, experts say|url=https://phys.org/news/2013-12-humans-smarter-animals-experts.html|access-date=2020-10-24|website=phys.org|language=en}}</ref>

There are some traits that, although not strictly unique, do set humans apart from other animals.<ref>{{cite web| vauthors = Robson D |title=We've got human intelligence all wrong|url=https://www.bbc.com/future/article/20161108-weve-got-human-intelligence-all-wrong|access-date=2020-10-24|website=www.bbc.com|language=en}}</ref> Humans may be the only animals who have [[episodic memory#In animals|episodic memory]] and who can engage in "[[mental time travel#Evolution and human uniqueness|mental time travel]]".<ref>{{cite news | vauthors = Owen J |date=26 February 2015|title=Many Animals—Including Your Dog—May Have Horrible Short-Term Memories |work=National Geographic News|url=https://www.nationalgeographic.com/animals/article/150225-dogs-memories-animals-chimpanzees-science-mind-psychology |access-date=6 September 2020}}</ref> Even compared with other social animals, humans have an unusually high degree of flexibility in their facial expressions.<ref>{{cite journal | vauthors = Schmidt KL, Cohn JF | title = Human facial expressions as adaptations: Evolutionary questions in facial expression research | journal = American Journal of Physical Anthropology | volume = 116 | issue = S33 | pages = 3–24 | date = 2001 | pmid = 11786989 | pmc = 2238342 | doi = 10.1002/ajpa.20001 }}</ref> Humans are the only animals known to cry emotional tears.<ref>{{cite news | vauthors = Moisse K |date= 5 January 2011 |title=Tears in Her Eyes: A Turnoff for Guys?|language=en|work=ABC News (American)|url=https://abcnews.go.com/Health/MindMoodNews/womens-tears-chemical-turnoff-men/story?id=12540975|access-date=22 April 2020}}</ref> Humans are one of the few animals able to self-recognize in [[mirror test]]s<ref>{{cite news| vauthors = Deleniv S |date=2018|title=The 'me' illusion: How your brain conjures up your sense of self|work=New Scientist|url=https://www.newscientist.com/article/mg23931940-100-the-me-illusion-how-your-brain-conjures-up-your-sense-of-self/|access-date=22 April 2020}}</ref> and there is also debate over to what extent humans are the only animals with a [[theory of mind]].<ref>{{cite news | vauthors = Beck J |date=2019|title=Can We Really Know What Animals Are Thinking?|work=Snopes |url=https://www.snopes.com/news/2019/09/07/can-we-really-know-what-animals-are-thinking/|access-date=22 April 2020}}</ref>

Humans are generally [[Diurnality|diurnal]]. The average sleep requirement is between seven and nine hours per day for an adult and nine to ten hours per day for a child; elderly people usually sleep for six to seven hours. Having less sleep than this is common among humans, even though [[sleep deprivation]] can have negative health effects. A sustained restriction of adult sleep to four hours per day has been shown to correlate with changes in physiology and mental state, including reduced memory, fatigue, aggression, and bodily discomfort.<ref name=Grandner2010>{{cite journal | vauthors = Grandner MA, Patel NP, Gehrman PR, Perlis ML, Pack AI | title = Problems associated with short sleep: bridging the gap between laboratory and epidemiological studies | journal = Sleep Medicine Reviews | volume = 14 | issue = 4 | pages = 239–47 | date = August 2010 | pmid = 19896872 | pmc = 2888649 | doi = 10.1016/j.smrv.2009.08.001 }}</ref><!--cites previous two sentences-->

During sleep humans dream, where they experience sensory images and sounds. Dreaming is stimulated by the [[pons]] and mostly occurs during the [[REM phase of sleep]].<ref>{{cite web| vauthors = Ann L |date=January 27, 2005|title=HowStuffWorks "Dreams: Stages of Sleep"|url=https://science.howstuffworks.com/environmental/life/human-biology/dream2.htm|url-status=dead|archive-url=https://web.archive.org/web/20120515212353/https://science.howstuffworks.com/environmental/life/human-biology/dream2.htm|archive-date=May 15, 2012|access-date=August 11, 2012|publisher=Science.howstuffworks.com}}</ref> The length of a dream can vary, from a few seconds up to 30 minutes.<ref name=Hobson>{{cite journal | vauthors = Hobson JA | title = REM sleep and dreaming: towards a theory of protoconsciousness | journal = Nature Reviews. Neuroscience | volume = 10 | issue = 11 | pages = 803–13 | date = November 2009 | pmid = 19794431 | doi = 10.1038/nrn2716 | s2cid = 205505278 }}</ref> Humans have three to five dreams per night, and some may have up to seven;<ref>{{cite book | vauthors = Empson J | date = 2002 | title = Sleep and dreaming | edition = 3rd | location = New York | publisher = Palgrave/St. Martin's Press }}</ref> however most dreams are immediately or quickly forgotten.<ref>{{cite web | vauthors = Cherry K | date = 2015 | url = https://psychology.about.com/od/statesofconsciousness/tp/facts-about-dreams.htm | title = 10 Facts About Dreams: What Researchers Have Discovered About Dreams | archive-url = https://web.archive.org/web/20160221091846/https://psychology.about.com/od/statesofconsciousness/tp/facts-about-dreams.htm| archive-date= 21 February 2016 | work = About Education: Psychology | publisher = About.com }}</ref> They are more likely to remember the dream if awakened during the REM phase. The events in dreams are generally outside the control of the dreamer, with the exception of [[lucid dream]]ing, where the dreamer is [[self-aware]].<ref>{{cite web| vauthors = Lite J |date=July 29, 2010|title=How Can You Control Your Dreams?|url=https://www.scientificamerican.com/article/how-to-control-dreams/|url-status=live|archive-url=https://web.archive.org/web/20150202070145/https://www.scientificamerican.com/article/how-to-control-dreams/|archive-date=February 2, 2015|website=Scientific America}}</ref> Dreams can at times make a [[Creativity|creative]] thought occur or give a sense of [[Artistic inspiration|inspiration]].<ref>{{cite book | vauthors = Domhoff W | date = 2002 | title = The scientific study of dreams | publisher = APA Press }}</ref>

===Consciousness and thought===

{{Main|Consciousness|Cognition}}

Human consciousness, at its simplest, is "[[sentience]] or [[awareness]] of internal or external existence".<ref name="consciousness">{{cite dictionary|title=Consciousness|dictionary=Merriam-Webster|access-date=June 4, 2012|url=https://www.merriam-webster.com/dictionary/consciousness}}</ref> Despite centuries of analyses, definitions, explanations and debates by philosophers and scientists, consciousness remains puzzling and controversial,<ref name="van_Gulick2004">{{cite encyclopedia| vauthors = van Gulick R |year=2004|title=Consciousness|encyclopedia=Stanford Encyclopedia of Philosophy |url=https://plato.stanford.edu/entries/consciousness/ |publisher=Metaphysics Research Lab, Stanford University}}</ref> being "at once the most familiar and most mysterious aspect of our lives".<ref>{{cite book| vauthors = Schneider S, Velmans M |author2-link=Max Velmans |title=The Blackwell Companion to Consciousness |publisher=Wiley|year=2008|isbn=978-0-470-75145-9| veditors = Velmans M, Schneider S |chapter=Introduction}}</ref> The only widely agreed notion about the topic is the intuition that it exists.<ref>{{cite book| vauthors = Searle J |title=The Oxford companion to philosophy|publisher=Oxford University Press|year=2005|isbn=978-0-19-926479-7| veditors = Honderich T|chapter=Consciousness|author-link=John Searle}}</ref> Opinions differ about what exactly needs to be studied and explained as consciousness. Some philosophers divide consciousness into phenomenal consciousness, which is sensory experience itself, and access consciousness, which can be used for reasoning or directly controlling actions.<ref name="Bl">{{cite journal | vauthors = Block N | title = On a confusion about a function of consciousness. | journal = Behavioral and Brain Sciences | date = June 1995 | volume = 18 | issue = 2 | pages = 227–47 | doi = 10.1017/S0140525X00038474 | s2cid = 246244859 }}</ref> It is sometimes synonymous with 'the mind', and at other times, an aspect of it. Historically it is associated with [[introspection]], private [[thought]], [[imagination]] and [[Volition (psychology)|volition]].<ref name="JJ3">{{cite book|vauthors=Jaynes J|url=https://s-f-walker.org.uk/pubsebooks/pdfs/Julian_Jaynes_The_Origin_of_Consciousness.pdf|title=The Origin of Consciousness in the Breakdown of the Bicameral Mind|publisher=Houghton Mifflin|year=2000|isbn=0-618-05707-2|author-link=Julian Jaynes|orig-year=1976|access-date=25 October 2020|archive-date=7 August 2019|archive-url=https://web.archive.org/web/20190807100304/https://s-f-walker.org.uk/pubsebooks/pdfs/Julian_Jaynes_The_Origin_of_Consciousness.pdf|url-status=dead}}</ref> It now often includes some kind of [[experience]], [[cognition]], [[feeling]] or [[perception]]. It may be 'awareness', or '[[Meta-cognition|awareness of awareness]]', or [[self-awareness]].<ref name="Rochat 2003 717–731">{{cite journal | vauthors = Rochat P | title = Five levels of self-awareness as they unfold early in life | journal = Consciousness and Cognition | volume = 12 | issue = 4 | pages = 717–31 | date = December 2003 | pmid = 14656513 | doi = 10.1016/s1053-8100(03)00081-3 | s2cid = 10241157 }}</ref> There might be different levels or [[Higher-order theories of consciousness|orders of consciousness]],<ref name="Carruthers2011">{{cite web| vauthors = Carruthers P |date=15 Aug 2011|title=Higher-Order Theories of Consciousness|url=https://plato.stanford.edu/entries/consciousness-higher/|access-date=31 August 2014|website=Stanford Encyclopedia of Philosophy}}</ref> or different kinds of consciousness, or just one kind with different features.<ref name="Antony2001">{{cite journal| vauthors = Antony MV |year=2001|title=Is ''consciousness'' ambiguous?|journal=Journal of Consciousness Studies|volume=8|pages=19–44}}</ref>

The process of acquiring knowledge and understanding through thought, experience, and the senses is known as cognition.<ref>{{cite web|title=Cognition|url=https://www.lexico.com/definition/cognition|access-date=6 May 2020|website=Lexico|publisher=[[Oxford University Press]] and [[Dictionary.com]]}}</ref> The human brain [[perception|perceives]] the external world through the [[sense]]s, and each individual human is influenced greatly by his or her experiences, leading to [[subjectivity|subjective]] views of [[existence]] and the passage of time.<ref>{{cite book | vauthors = Glattfelder JB | chapter = The Consciousness of Reality|date=2019 |title = Information—Consciousness—Reality: How a New Understanding of the Universe Can Help Answer Age-Old Questions of Existence|pages=515–595| veditors = Glattfelder JB |series=The Frontiers Collection|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-030-03633-1_14|isbn=978-3-030-03633-1 | s2cid = 189379814}}</ref> The nature of thought is central to psychology and related fields. [[Cognitive psychology]] studies [[cognition]], the [[mental function|mental processes]] underlying behavior.<ref>{{cite web|title=American Psychological Association (2013). Glossary of psychological terms|url=https://www.apa.org/research/action/glossary.aspx|access-date=2014-08-13|publisher=Apa.org}}</ref> Largely focusing on the development of the human mind through the life span, [[developmental psychology]] seeks to understand how people come to perceive, understand, and act within the world and how these processes change as they age.<ref>{{cite web|title=Developmental Psychology Studies Human Development Across the Lifespan|url=https://www.apa.org/action/science/developmental/index.aspx|url-status=dead|archive-url=https://web.archive.org/web/20140709054242/https://www.apa.org/action/science/developmental/index.aspx|archive-date=2014-07-09|access-date=2017-08-28|website=www.apa.org|language=en}}</ref><ref>{{cite book| vauthors = Burman E |title=Deconstructing Developmental Psychology|publisher=Routledge|year=2017|isbn=978-1-138-84695-1|location=New York, NY }}</ref> This may focus on intellectual, cognitive, neural, social, or [[moral development]]. [[Psychologists]] have developed intelligence tests and the concept of [[intelligence quotient]] in order to assess the relative intelligence of human beings and study its [[Distribution (mathematics)|distribution]] among population.<ref>{{Cite journal| vauthors = Colom R |date=2004-01-01|title=Intelligence Assessment |journal=Encyclopedia of Applied Psychology|language=en|pages=307–314|doi=10.1016/B0-12-657410-3/00510-9|isbn=9780126574104}}</ref>

 

Human motivation is not yet wholly understood. From a psychological perspective, [[Maslow's hierarchy of needs]] is a well-established theory that can be defined as the process of satisfying certain needs in ascending order of complexity.<ref>{{cite web|url=https://www.simplypsychology.org/maslow.html|title=Maslow's Hierarchy of Needs| vauthors = McLeod S |date=20 March 2020|website=Simplypsychology.org|publisher=Simply Scholar Limited|access-date=4 April 2020|quote=Maslow's hierarchy of needs is a motivational theory in psychology comprising a five-tier model of human needs, often depicted as hierarchical levels within a pyramid. Needs lower down in the hierarchy must be satisfied before individuals can attend to needs higher up.}}</ref> From a more general, philosophical perspective, human motivation can be defined as a commitment to, or withdrawal from, various goals requiring the application of human ability. Furthermore, [[incentive]] and [[preference]] are both factors, as are any perceived links between incentives and preferences. [[Volition (psychology)|Volition]] may also be involved, in which case willpower is also a factor. Ideally, both motivation and volition ensure the selection, striving for, and [[Realisation (metrology)|realization]] of goals in an optimal manner, a [[Function (biology)|function]] beginning in childhood and continuing throughout a lifetime in a process known as [[socialization]].<ref>{{cite book| vauthors = Heckhausen J, Heckhausen H |date=28 March 2018|title=Motivation and Action|location=Introduction and Overview|publisher=Springer, Cham|page=1|isbn=978-3-319-65093-7|doi=10.1007/978-3-319-65094-4_1}}</ref>

 

Emotions are [[biological]] states associated with the nervous system<ref>{{cite journal | vauthors = Damasio AR | title = Emotion in the perspective of an integrated nervous system | journal = Brain Research. Brain Research Reviews | volume = 26 | issue = 2–3 | pages = 83–6 | date = May 1998 | pmid = 9651488 | doi = 10.1016/s0165-0173(97)00064-7 | s2cid = 8504450 }}</ref><ref>{{cite book| vauthors = Ekman P, Davidson RJ |title=The Nature of emotion : fundamental questions|date=1994|publisher=Oxford University Press|isbn=978-0-19-508944-8|location=New York|pages=291–93|quote=Emotional processing, but not emotions, can occur unconsciously.}}</ref> brought on by [[Neurophysiology|neurophysiological]] changes variously associated with thoughts, feelings, behavioral responses, and a degree of [[pleasure]] or [[Suffering|displeasure]].<ref>{{cite journal | vauthors = Cabanac M | date = 2002 | title = What is emotion? | journal = Behavioural Processes | volume = 60 | issue = 2 | pages = 69–83 | quote = Emotion is any mental experience with high intensity and high hedonic content (pleasure/displeasure) | doi = 10.1016/S0376-6357(02)00078-5 | pmid = 12426062 | s2cid = 24365776 }}</ref><ref name="Schacter">{{cite book| vauthors = Scirst DL |url= https://archive.org/details/psychology0000scha/page/310 |title=Psychology Second Edition|publisher=Worth Publishers|year=2011|isbn=978-1-4292-3719-2|location=New York, NY|page=[https://archive.org/details/psychology0000scha/page/310 310]}}</ref> They are often [[Reciprocal influence|intertwined]] with [[Mood (psychology)|mood]], [[temperament]], [[Personality psychology|personality]], [[disposition]], [[creativity]],<ref>{{cite journal | vauthors = Averill JR | title = Individual differences in emotional creativity: structure and correlates | journal = Journal of Personality | volume = 67 | issue = 2 | pages = 331–71 | date = April 1999 | pmid = 10202807 | doi = 10.1111/1467-6494.00058 }}</ref> and motivation. Emotion has a significant influence on human behavior and their ability to learn.<ref>{{cite journal | vauthors = Tyng CM, Amin HU, Saad MN, Malik AS | title = The Influences of Emotion on Learning and Memory | journal = Frontiers in Psychology | volume = 8 | page = 1454 | date = 2017 | pmid = 28883804 | pmc = 5573739 | doi = 10.3389/fpsyg.2017.01454 | doi-access = free }}</ref> Acting on extreme or uncontrolled emotions can lead to social disorder and crime,<ref>{{cite book| vauthors = Van Gelder JL |url= https://www.researchgate.net/publication/317042659 |title=Oxford Bibliographies in Criminology|publisher=Oxford University Press|date=November 2016| veditors = Wright R |chapter=Emotions in Criminal Decision Making}}</ref> with studies showing criminals may have a lower emotional intelligence than normal.<ref>{{cite journal | vauthors = Sharma N, Prakash O, Sengar KS, Chaudhury S, Singh AR | title = The relation between emotional intelligence and criminal behavior: A study among convicted criminals | journal = Industrial Psychiatry Journal | volume = 24 | issue = 1 | pages = 54–8 | date = 2015 | pmid = 26257484 | pmc = 4525433 | doi = 10.4103/0972-6748.160934 }}</ref>

 

 

For humans, sexuality involves [[biological]], [[erotic]], [[Physical intimacy|physical]], [[Emotional intimacy|emotional]], [[social]], or [[Spirituality|spiritual]] feelings and behaviors.<ref name="S. Greenberg">{{cite book| vauthors = Greenberg JS, Bruess CE, Oswalt SB |url= https://books.google.com/books?id=8iarCwAAQBAJ&pg=PA4 |title=Exploring the Dimensions of Human Sexuality|publisher=[[Jones & Bartlett Publishers]]|year=2016|isbn=978-1-284-08154-1|pages=4–10|quote=Human sexuality is a part of your total personality. It involves the interrelationship of biological, psychological, and sociocultural dimensions. [...] It is the total of our physical, emotional, and spiritual responses, thoughts, and feelings.|access-date=21 June 2017}}</ref><ref name="Bolin">{{cite book| vauthors = Bolin A, Whelehan P |url=https://books.google.com/books?id=qrPHYok19v8C&pg=PA32|title=Human Sexuality: Biological, Psychological, and Cultural Perspectives|publisher=[[Taylor & Francis]]|year=2009|isbn=978-0-7890-2671-2|pages=32–42}}</ref> Because it is a broad term, which has varied with historical contexts over time, it lacks a precise definition.<ref name="Bolin" /> The biological and physical aspects of sexuality largely concern the [[Human reproduction|human reproductive functions]], including the [[human sexual response cycle]].<ref name="S. Greenberg" /><ref name="Bolin" /> Sexuality also affects and is affected by cultural, political, legal, philosophical, [[Morality|moral]], [[ethical]], and religious aspects of life.<ref name="S. Greenberg" /><ref name="Bolin" /> Sexual desire, or ''[[libido]]'', is a basic mental state present at the beginning of sexual behavior. Studies show that men desire sex more than women and [[Masturbation|masturbate]] more often.<ref>{{cite journal| vauthors = Younis I, Abdel-Rahman SH |date=2013|title=Sex difference in libido |journal=Human Andrology|language=en-US|volume=3|issue=4|pages=85–89|doi=10.1097/01.XHA.0000432482.01760.b0|s2cid=147235090}}</ref>

 

Humans can fall anywhere along a continuous scale of [[sexual orientation]],<ref name="APASO">{{cite web|title=Sexual orientation, homosexuality and bisexuality|url=https://www.apa.org/helpcenter/sexual-orientation.aspx|archive-url=https://web.archive.org/web/20130808032050/https://www.apa.org/helpcenter/sexual-orientation.aspx|archive-date=8 August 2013|access-date=10 August 2013|publisher=[[American Psychological Association]]}}</ref> although most humans are [[heterosexual]].<ref name=Bailey16/><ref name=LeVay/> While [[homosexuality|homosexual]] behavior [[Homosexual behavior in animals|occurs in some other animals]], only humans and [[Sheep|domestic sheep]] have so far been found to exhibit exclusive preference for same-sex relationships.<ref name=Bailey16/> Most evidence supports nonsocial, [[biology and sexual orientation|biological causes of sexual orientation]],<ref name="Bailey16">{{cite journal | vauthors = Bailey JM, Vasey PL, Diamond LM, Breedlove SM, Vilain E, Epprecht M | title = Sexual Orientation, Controversy, and Science | journal = Psychological Science in the Public Interest | volume = 17 | issue = 2 | pages = 45–101 | date = September 2016 | pmid = 27113562 | doi = 10.1177/1529100616637616 | doi-access = free }}</ref> as cultures that are very tolerant of homosexuality do not have significantly higher rates of it.<ref name="LeVay">{{cite book| vauthors = LeVay S |url=https://books.google.com/books?id=HmQFFfa03nkC|title=Gay, Straight, and the Reason Why: The Science of Sexual Orientation|date=2017|publisher=Oxford University Press|isbn=978-0-19-975296-6|pages=8, 19}}</ref><ref name="Balthazart">{{cite book| vauthors = Balthazart J |url=https://books.google.com/books?id=3fjGjlcVINkC|title=The Biology of Homosexuality|date=2012|publisher=Oxford University Press|isbn=978-0-19-983882-0|pages=13–14}}</ref> Research in [[neuroscience]] and [[genetics]] suggests that other aspects of human sexuality are biologically influenced as well.<ref name=Buss2003>{{cite book | vauthors = Buss DM |year=2003 |title=The Evolution of Desire: Strategies of Human Mating. | edition = Revised |location=New York City |publisher=Basic Books |isbn=978-0-465-00802-5 |url=https://archive.org/details/evolutionofdesir00buss }}</ref>

 

 

|data2=[[Christianity]], [[Islam]], [[Hinduism]], [[Buddhism]], [[folk religion]]s, [[Sikhism]], [[Judaism]], [[Irreligion|unaffiliated]]

Humanity's unprecedented set of intellectual skills were a key factor in the species' eventual technological advancement and concomitant domination of the biosphere.<ref>{{cite book | vauthors = Ord T |title=The Precipice: Existential Risk and the Future of Humanity |date=2020 | location = New York |publisher=Hachette Books |isbn=978-0-316-48489-3 |quote=Homo sapiens and our close relatives may have some unique physical attributes, such as our dextrous hands, upright walking and resonant voices. However, these on their own cannot explain our success. They went together with our intelligence...}}</ref> Disregarding extinct hominids, humans are the only animals known to teach generalizable information,<ref>{{cite news | vauthors = Goldman JG |title=Pay attention… time for lessons at animal school |url= https://www.bbc.com/future/article/20121005-pay-attention-its-animal-school |access-date=22 April 2020 |work=bbc.com |date=2012 |language=en}}</ref> innately deploy recursive [[embedding]] to generate and communicate complex concepts,<ref>{{cite journal | vauthors = Winkler M, Mueller JL, Friederici AD, Männel C | title = Infant cognition includes the potentially human-unique ability to encode embedding | journal = Science Advances | volume = 4 | issue = 11 | pages = eaar8334 | date = November 2018 | pmid = 30474053 | pmc = 6248967 | doi = 10.1126/sciadv.aar8334 | doi-access = free | bibcode = 2018SciA....4.8334W }}</ref> engage in the "[[folk physics]]" required for competent tool design,<ref>{{cite journal | vauthors = Johnson-Frey SH | title = What's so special about human tool use? | journal = Neuron | volume = 39 | issue = 2 | pages = 201–4 | date = July 2003 | pmid = 12873378 | doi = 10.1016/S0896-6273(03)00424-0 | s2cid = 18437970 }}</ref><ref>{{cite journal | vauthors = Emery NJ, Clayton NS | title = Tool use and physical cognition in birds and mammals | journal = Current Opinion in Neurobiology | volume = 19 | issue = 1 | pages = 27–33 | date = February 2009 | pmid = 19328675 | doi = 10.1016/j.conb.2009.02.003 | quote = In short, the evidence to date that animals have an understanding of folk physics is at best mixed. | s2cid = 18277620 }}</ref> or cook food in the wild.<ref>{{cite news | vauthors = Lemonick MD | date = 3 June 2015 |title= Chimps Can't Cook, But Maybe They'd Like To |url=https://www.nationalgeographic.com/news/2015/06/150602-chimp-cooking-evolution-human-brain-science/ |access-date=22 April 2020 |work=National Geographic News }}</ref> Teaching and learning preserves the cultural and ethnographic identity of human societies.<ref>{{cite journal| vauthors = Vakhitova T, Gadelshina L |date=2015-06-02|title=The Role and Importance of the Study of Economic Subjects in the Implementation of the Educational Potential of Education |journal=Procedia - Social and Behavioral Sciences|series=The Proceedings of 6th World Conference on educational Sciences|language=en|volume=191|pages=2565–2567|doi=10.1016/j.sbspro.2015.04.690|issn=1877-0428}}</ref> Other traits and behaviors that are mostly unique to humans include starting fires,<ref>{{cite news | vauthors = McKie R |date=9 October 2018|title=The Book of Humans by Adam Rutherford review – a pithy homage to our species|language=en|work=The Guardian|url=https://www.theguardian.com/books/2018/oct/09/the-book-of-humans-adam-rutherford-review|access-date=22 April 2020}}</ref> [[phoneme]] structuring<ref>{{cite news| vauthors = Nicholls H |date=29 June 2015|title=Babblers speak to the origin of language|work=The Guardian|url=https://www.theguardian.com/science/animal-magic/2015/jun/29/babblers-birds-origin-evolution-language|access-date=22 April 2020}}</ref> and [[vocal learning]].<ref>{{cite news| vauthors = Dasgupta S |date=2015|title=Can any animals talk and use language like humans?|language=en|work=bbc.com|url=https://www.bbc.com/earth/story/20150216-can-any-animals-talk-like-humans|access-date=22 April 2020|quote=Most animals are not vocal learners.}}</ref>

{{main article|Language|Language family}}

 

While many species [[animal communication|communicate]], [[language]] is unique to humans, a defining feature of humanity, and a [[cultural universal]].<ref>{{cite web | vauthors = Scott-Phillips TC, Blythe RA | date = 18 September 2013 |title=Why is language unique to humans? | publisher = Royal Society|url=https://royalsociety.org/news/2013/language-unique-humans/|access-date=2020-10-24 |language=en-gb}}</ref> Unlike the limited systems of other animals, human language is open—an infinite number of meanings can be produced by combining a limited number of symbols.<ref>{{cite journal | vauthors = Pagel M | title = Q&A: What is human language, when did it evolve and why should we care? | journal = BMC Biology | volume = 15 | issue = 1 | page = 64 | date = July 2017 | pmid = 28738867 | pmc = 5525259 | doi = 10.1186/s12915-017-0405-3 }}</ref><ref>{{cite journal| vauthors = Fitch WT |date=2010-12-04|title=Language evolution: How to hear words long silenced |journal=New Scientist|language=en|volume=208|issue=2789|pages=ii–iii|doi=10.1016/S0262-4079(10)62961-2|bibcode=2010NewSc.208D...2F|issn=0262-4079}}</ref> Human language also has the capacity of [[Displacement (linguistics)|displacement]], using words to represent things and happenings that are not presently or locally occurring but reside in the shared imagination of interlocutors.<ref name="Revolution" />

 

Language differs from other forms of communication in that it is [[Origin of speech#Modality-independence|modality independent]]; the same meanings can be conveyed through different media, audibly in [[speech]], visually by [[sign language]] or writing, and through tactile media such as [[braille]].<ref>{{cite book | vauthors = Lian A | chapter = The Modality-Independent Capacity of Language: A Milestone of Evolution|date=2016 | title = Language Evolution and Developmental Impairments|pages=229–255| veditors = Lian A |place=London|publisher=Palgrave Macmillan UK|language=en|doi=10.1057/978-1-137-58746-6_7|isbn=978-1-137-58746-6 }}</ref> Language is central to the communication between humans, and to the sense of identity that unites nations, cultures and ethnic groups.<ref>{{cite web|title=Culture {{!}} United Nations For Indigenous Peoples|url=https://www.un.org/development/desa/indigenouspeoples/mandated-areas1/culture.html|access-date=2020-10-24|website=www.un.org|date=5 June 2015}}</ref> There are approximately six thousand different languages currently in use, including sign languages, and many thousands more that are [[extinct language|extinct]].<ref name="Comrie1996">{{cite book | vauthors = Comrie B, Polinsky M, Matthews S |title=The Atlas of Languages: The Origin and Development of Languages Throughout the World |year=1996 |publisher=Facts on File |location=New York City |pages=13–15 |isbn=978-0-8160-3388-1}}</ref>

 

{{Main|The arts||}}Human arts can take many forms including [[Visual arts|visual]], [[Literary arts|literary]] and [[Performing arts|performing]]. Visual art can range from [[painting]]s and [[sculpture]]s to [[film]], [[interaction design]] and [[architecture]].<ref>{{Cite book| vauthors = Mavrody S |url=https://books.google.com/books?id=tBqgBQAAQBAJ|title=Visual Art Forms: Traditional to Digital|publisher=Sergey's HTML5 & CSS3|year=2013|isbn=978-0-9833867-5-9|language=en}}</ref> Literary arts can include [[prose]], [[poetry]] and [[drama]]s; while the performing arts generally involve [[theatre]], [[music]] and [[dance]].<ref>{{cite web|date=2020|title=Types of Literary Arts and Their Understanding – bookfestivalscotland.com|url=https://bookfestivalscotland.com/types-of-literary-arts-and-their-understanding/|access-date=2021-05-05|website=Bookfestival Scotland|language=en-UK}}</ref><ref>{{cite web|title=Bachelor of Performing Arts|url=https://www.otago.ac.nz/performing-arts/otago056890.pdf|website=[[University of Otago]]}}</ref> Humans often combine the different forms (for example, music videos).<ref>{{Cite journal| vauthors = Brown S |date=2018-10-24|title=Toward a Unification of the Arts|journal=Frontiers in Psychology|volume=9|page=1938|doi=10.3389/fpsyg.2018.01938|issn=1664-1078|pmc=6207603|pmid=30405470|doi-access=free}}</ref> Other entities that have been described as having artistic qualities include [[Culinary arts|food preparation]], [[Video games as an art form|video games]] and [[medicine]].<ref>{{cite web |date=2019-10-21|title=Culinary arts - How cooking can be an art|url=https://www.northernartprize.org.uk/culinary-arts-cooking-can-art|access-date=2021-05-05|website=Northern Contemporary Art|language=en-US}}</ref><ref>{{Cite journal| vauthors = Smuts A |date=2005-01-01|title=Are Video Games Art?|url=https://digitalcommons.risd.edu/liberalarts_contempaesthetics/vol3/iss1/6|journal=Contemporary Aesthetics (Journal Archive)|volume=3|issue=1}}</ref><ref>{{cite journal | vauthors = Cameron IA, Pimlott N | title = Art of medicine | journal = Canadian Family Physician | volume = 61 | issue = 9 | pages = 739–40 | date = September 2015 | pmid = 26371092 | pmc = 4569099 }}</ref> As well as providing entertainment and transferring knowledge, the arts are also used for [[The arts and politics|political purposes]].<ref>{{Cite journal| vauthors = Bird G |date=2019-06-07|title=Rethinking the role of the arts in politics: lessons from the Négritude movement |journal=International Journal of Cultural Policy|language=en|volume=25|issue=4|pages=458–470|doi=10.1080/10286632.2017.1311328|s2cid=151443044|issn=1028-6632}}</ref> [[File:British Museum Flood Tablet.jpg|thumb|upright|The [[deluge (mythology)|Deluge]] tablet of [[Epic of Gilgamesh|the ''Gilgamesh'' epic]] in [[Akkadian language|Akkadian]]]]

 

[[Art]] is a defining characteristic of humans and there is evidence for a relationship between creativity and language.<ref name=":4">{{cite journal | vauthors = Morriss-Kay GM | title = The evolution of human artistic creativity | journal = Journal of Anatomy | volume = 216 | issue = 2 | pages = 158–76 | date = February 2010 | pmid = 19900185 | pmc = 2815939 | doi = 10.1111/j.1469-7580.2009.01160.x }}</ref> The earliest evidence of art was shell engravings made by ''Homo erectus'' 300,000 years before modern humans evolved.<ref>{{cite journal | vauthors = Joordens JC, d'Errico F, Wesselingh FP, Munro S, de Vos J, Wallinga J, Ankjærgaard C, Reimann T, Wijbrans JR, Kuiper KF, Mücher HJ, Coqueugniot H, Prié V, Joosten I, van Os B, Schulp AS, Panuel M, van der Haas V, Lustenhouwer W, Reijmer JJ, Roebroeks W | display-authors = 6 | title = Homo erectus at Trinil on Java used shells for tool production and engraving | journal = Nature | volume = 518 | issue = 7538 | pages = 228–31 | date = February 2015 | pmid = 25470048 | doi = 10.1038/nature13962 | s2cid = 4461751 | bibcode = 2015Natur.518..228J }}</ref> Art attributed to ''H. sapiens'' existed at least 75,000 years ago, with jewellery and drawings found in caves in South Africa.<ref>{{cite news| vauthors = St Fleur N |date=12 September 2018|title=Oldest Known Drawing by Human Hands Discovered in South African Cave|newspaper=The New York Times|url=https://www.nytimes.com/2018/09/12/science/oldest-drawing-ever-found.html|access-date=20 September 2018}}</ref><ref>{{cite news| vauthors = Radford T |date=2004-04-16|title=World's oldest jewellery found in cave|language=en-GB|work=The Guardian|url=https://www.theguardian.com/world/2004/apr/16/artsandhumanities.arts|access-date=2020-09-23|issn=0261-3077}}</ref> There are various hypotheses as to why humans have [[Adaptation|adapted]] to the arts. These include allowing them to better problem solve issues, providing a means to control or influence other humans, encouraging cooperation and contribution within a society or increasing the chance of attracting a potential mate.<ref>{{cite book| vauthors = Dissanayake E |title=World Art Studies: Exploring Concepts and Approaches|publisher=Valiz|year=2008| veditors = Zijlmans K, van Damme W |location=Amsterdam|pages=241–263|chapter=The Arts after Darwin: Does Art have an Origin and Adaptive Function? }}</ref> The use of imagination developed through art, combined with logic may have given early humans an evolutionary advantage.<ref name=":4" />

 

Evidence of humans engaging in musical activities predates cave art and so far music has been [[Cultural universal|practiced by virtually all known human cultures]].<ref name=":2">{{cite journal | vauthors = Morley I | title = A multi-disciplinary approach to the origins of music: perspectives from anthropology, archaeology, cognition and behaviour | journal = Journal of Anthropological Sciences = Rivista di Antropologia | volume = 92 | issue = 92 | pages = 147–77 | date = 2014 | pmid = 25020016 | doi = 10.4436/JASS.92008 }}</ref> There exists a wide variety of [[music genre]]s and [[ethnic music]]s; with humans' musical abilities being related to other abilities, including complex social human behaviours.<ref name=":2" /> It has been shown that human brains respond to music by becoming synchronized with the rhythm and beat, a process called [[Entrainment (biomusicology)|entrainment]].<ref>{{cite journal | vauthors = Trost W, Frühholz S, Schön D, Labbé C, Pichon S, Grandjean D, Vuilleumier P | title = Getting the beat: entrainment of brain activity by musical rhythm and pleasantness | journal = NeuroImage | volume = 103 | pages = 55–64 | date = December 2014 | pmid = 25224999 | doi = 10.1016/j.neuroimage.2014.09.009 | s2cid = 4727529 }}</ref> Dance is also a form of human expression found in all cultures<ref>{{cite journal | vauthors = Karpati FJ, Giacosa C, Foster NE, Penhune VB, Hyde KL | title = Dance and the brain: a review | journal = Annals of the New York Academy of Sciences | volume = 1337 | issue = 1 | pages = 140–6 | date = March 2015 | pmid = 25773628 | doi = 10.1111/nyas.12632 | s2cid = 206224849 | bibcode = 2015NYASA1337..140K }}</ref> and may have evolved as a way to help early humans communicate.<ref>{{cite web | date = 22 March 2010| vauthors = Chow D |title=Why Do Humans Dance?|url=https://www.livescience.com/8132-humans-dance.html|access-date=2020-09-21|website=livescience.com|language=en}}</ref> Listening to music and observing dance stimulates the [[orbitofrontal cortex]] and other pleasure sensing areas of the brain.<ref>{{cite web | vauthors = Krakauer J | date = 26 September 2008 |title=Why do we like to dance--And move to the beat?|url=https://www.scientificamerican.com/article/experts-dance/|access-date=2020-09-21|website=Scientific American|language=en}}</ref>

 

Unlike speaking, reading and writing does not come naturally to humans and must be taught.<ref>{{cite web| vauthors = Prior KS |date=2013-06-21|title=How Reading Makes Us More Human|url=https://www.theatlantic.com/national/archive/2013/06/how-reading-makes-us-more-human/277079/|access-date=2020-09-23|website=The Atlantic|language=en-US}}</ref> Still, [[literature]] has been present before the invention of words and language, with 30,000-year-old paintings on walls inside some caves portraying a series of dramatic scenes.<ref name=":3">{{cite web| vauthors = Puchner M |title=How stories have shaped the world|url=https://www.bbc.com/culture/article/20180423-how-stories-have-shaped-the-world|access-date=2020-09-23|website=www.bbc.com|language=en}}</ref> One of the oldest surviving works of literature is the ''[[Epic of Gilgamesh]]'', first engraved on ancient [[Babylonia]]n tablets about 4,000 years ago.<ref>{{cite book| vauthors = Dalley S |title=Myths from Mesopotamia: Creation, the Flood, Gilgamesh, and Others|publisher=Oxford University Press|year=2000|isbn=978-0-19-283589-5|edition=revised|page=41}}</ref> Beyond simply passing down knowledge, the use and sharing of imaginative [[fiction]] through stories might have helped develop humans' capabilities for communication and increased the likelihood of securing a mate.<ref>{{cite journal| vauthors = Hernadi P |date=2001|title=Literature and Evolution|url=https://www.jstor.org/stable/3685504|journal=SubStance|volume=30|issue=1/2|pages=55–71|doi=10.2307/3685504|jstor=3685504|issn=0049-2426}}</ref> Storytelling may also be used as a way to provide the audience with moral lessons and encourage cooperation.<ref name=":3" />

Humans and humanity itself are often the subject of the arts. While most art focuses on individual humans or a small group, in literature, the genre of science fiction is known for tackling issues related to humanity as a whole - for example topics such as human evolution or the future of civilization.<ref>{{Cite book| vauthors = Gunn J |url=https://books.google.com/books?id=SQMQQyIaACYC&q=humanity|title=The Greenwood Encyclopedia of Science Fiction and Fantasy: Themes, Works, and Wonders|date=2005|publisher=Greenwood Publishing Group|isbn=978-0-313-32951-7| veditors = Westfahl G |pages=399–401|language=en|chapter=Humanity}}</ref>

[[File:JR-Maglev-MLX01-2.jpg|alt=Train running on a track|thumb|The [[SCMaglev]], the [[land speed record for rail vehicles|fastest train]] in the world clocking in at {{cvt|375|mph|0}} as of 2015<ref>{{cite news| vauthors = McCurry J |date=21 April 2015|title=Japan's Maglev Train Breaks World Speed Record with 600&nbsp;km/h Test Run |edition=U.S. |work=The Guardian |location=New York|url=https://www.theguardian.com/world/2015/apr/21/japans-maglev-train-notches-up-new-world-speed-record-in-test-run}}</ref>]]

Stone tools were used by proto-humans at least 2.5&nbsp;million years ago.<ref name="Clark1994">{{cite journal | vauthors = Clark JD, de Heinzelin J, Schick KD, Hart WK, White TD, WoldeGabriel G, Walter RC, Suwa G, Asfaw B, Vrba E | display-authors = 6 | title = African Homo erectus: old radiometric ages and young Oldowan assemblages in the Middle Awash Valley, Ethiopia | journal = Science | volume = 264 | issue = 5167 | pages = 1907–10 | date = June 1994 | pmid = 8009220 | doi = 10.1126/science.8009220 | bibcode = 1994Sci...264.1907C }}</ref> The use and manufacture of tools has been put forward as the ability that defines humans more than anything else<ref name=":7">{{cite web| date = 11 November 2009| vauthors = Choi CQ |title=Human Evolution: The Origin of Tool Use|url=https://www.livescience.com/7968-human-evolution-origin-tool.html|access-date=2020-10-09|website=livescience.com|language=en}}</ref> and has historically been seen as an important evolutionary step.<ref>{{cite journal | vauthors = Orban GA, Caruana F | title = The neural basis of human tool use | journal = Frontiers in Psychology | volume = 5 | page = 310 | date = 2014 | pmid = 24782809 | pmc = 3988392 | doi = 10.3389/fpsyg.2014.00310 | doi-access = free }}</ref> The technology became much more sophisticated about 1.8 million years ago,<ref name=":7" /> with the [[Control of fire by early humans|controlled use of fire]] beginning around 1&nbsp;million years ago.<ref name=":03">{{cite journal | vauthors = Berna F, Goldberg P, Horwitz LK, Brink J, Holt S, Bamford M, Chazan M | title = Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave, Northern Cape province, South Africa | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 109 | issue = 20 | pages = E1215-20 | date = May 2012 | pmid = 22474385 | pmc = 3356665 | doi = 10.1073/pnas.1117620109 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Gowlett JA | title = The discovery of fire by humans: a long and convoluted process | journal = Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences | volume = 371 | issue = 1696 | page = 20150164 | date = June 2016 | pmid = 27216521 | pmc = 4874402 | doi = 10.1098/rstb.2015.0164 }}</ref> The wheel and wheeled vehicles appeared simultaneously in several regions some time in the fourth millennium BC.<ref name=":14" /> The development of more complex tools and technologies allowed land to be [[Arable land|cultivated]] and animals to be [[Domestication|domesticated]], thus proving essential in the development of [[agriculture]]—what is known as the [[Neolithic Revolution]].<ref>{{cite web|date=2018|title=Neolithic Era Tools: Inventing a New Age|url=https://www.magellantv.com/articles/tools-of-the-neolithic-era-inventing-a-new-age|access-date=2020-10-09|website=MagellanTV|vauthors=Damiano J}}</ref>

China developed [[paper]], the [[printing press]], [[gunpowder]], the [[compass]] and [[List of Chinese inventions|other important inventions]].<ref>{{Cite book| vauthors = Deng Y, Wang P |url=https://www.worldcat.org/oclc/671710733|title=Ancient Chinese inventions|publisher=Cambridge University Press|year=2011|isbn=978-0-521-18692-6|edition=|location=Cambridge, UK|pages=13–14|oclc=671710733}}</ref> The continued improvements in [[smelting]] allowed [[forging]] of copper, bronze, iron and eventually [[steel]], which is used in [[railways]], [[skyscraper]]s and many other products.<ref>{{cite web| vauthors = Schifman J |date=2018-07-09|title=The Entire History of Steel|url=https://www.popularmechanics.com/technology/infrastructure/a20722505/history-of-steel/|access-date=2021-05-05|website=Popular Mechanics|language=en-US}}</ref> This coincided with the [[Industrial Revolution]], where the invention of automated machines brought major changes to humans' lifestyles.<ref>{{cite web | author = National Geographic Society |date=2020-01-09|title=Industrial Revolution and Technology|url=https://www.nationalgeographic.org/article/industrial-revolution-and-technology/|access-date=2020-10-09|website=National Geographic Society|language=en}}</ref> Modern technology is observed as [[Accelerating change|progressing exponentially]],<ref>{{Cite journal| vauthors = Roser M, Ritchie H |date=2013-05-11|title=Technological Progress|url=https://ourworldindata.org/technological-progress|journal=Our World in Data}}</ref> with major innovations in the 20th century including: [[Electricity generation|electricity]], [[penicillin]], [[semiconductor]]s, [[internal combustion engine]]s, the [[Internet]], [[Fertilizer|nitrogen fixing fertilisers]], [[airplane]]s, [[computer]]s, [[Car|automobiles]], [[Combined oral contraceptive pill|contraceptive pills]], [[nuclear fission]], the [[Green Revolution|green revolution]], [[radio]], scientific [[plant breeding]], [[rocket]]s, [[air conditioning]], [[television]] and the [[assembly line]].<ref>{{cite web| vauthors = Fallows J |date=2013-10-23|title=The 50 Greatest Breakthroughs Since the Wheel|url=https://www.theatlantic.com/magazine/archive/2013/11/innovations-list/309536/|access-date=2021-05-05|website=The Atlantic|language=en}}</ref>

===Religion and spirituality===

{{Main|Religion|Spirituality}}

Religion is generally defined as a [[belief]] system concerning the [[supernatural]], [[sacred]] or [[divinity|divine]], and practices, [[values]], institutions and [[ritual]]s associated with such belief. Some religions also have a [[moral code]]. The [[Evolutionary psychology of religion|evolution]] and the history of the [[Evolutionary origin of religions|first religions]] have recently become areas of active scientific investigation.<ref>{{cite web|title=Evolutionary Religious Studies: A New Field of Scientific Inquiry|url=https://evolution.binghamton.edu/religion/|url-status=dead|archive-url=https://web.archive.org/web/20090817171221/https://evolution.binghamton.edu/religion/|archive-date=17 August 2009}}</ref><ref name="Boyer2008">{{cite journal | vauthors = Boyer P | title = Being human: Religion: bound to believe? | journal = Nature | volume = 455 | issue = 7216 | pages = 1038–9 | date = October 2008 | pmid = 18948934 | doi = 10.1038/4551038a | bibcode = 2008Natur.455.1038B | s2cid = 205040781 }}</ref><ref name="Emmons2003">{{cite journal | vauthors = Emmons RA, Paloutzian RF | title = The psychology of religion | journal = Annual Review of Psychology | volume = 54 | issue = 1 | pages = 377–402 | year = 2003 | pmid = 12171998 | doi = 10.1146/annurev.psych.54.101601.145024 }}</ref><ref>{{cite web| vauthors = King BJ |date=2016-03-29|title=Chimpanzees: Spiritual But Not Religious?|url=https://www.theatlantic.com/science/archive/2016/03/chimpanzee-spirituality/475731/|access-date=2020-10-08|website=The Atlantic|language=en-US}}</ref> While the exact time when humans first became religious remains unknown, research shows credible evidence of religious behaviour from around the [[Middle Paleolithic]] era (45-200 [[Tya (unit)|thousand years ago]]).<ref>{{cite journal | vauthors = Culotta E | title = Origins. On the origin of religion | journal = Science | volume = 326 | issue = 5954 | pages = 784–7 | date = November 2009 | pmid = 19892955 | doi = 10.1126/science.326_784 | bibcode = 2009Sci...326..784C }}</ref> It may have evolved to play a role in helping enforce and encourage cooperation between humans.<ref>{{cite journal| vauthors = Atkinson QD, Bourrat P |title=Beliefs about God, the afterlife and morality support the role of supernatural policing in human cooperation|url=https://www.academia.edu/3430406|journal=Evolution and Human Behavior|year=2011|language=en|volume=32|issue=1|pages=41–49|doi=10.1016/j.evolhumbehav.2010.07.008|issn=1090-5138}}</ref>

There is no accepted academic definition of what constitutes religion.<ref name=":5">{{cite journal| vauthors = Idinopulos TA |date=1998|title=What Is Religion?|url=https://www.jstor.org/stable/24460821|journal=CrossCurrents|volume=48|issue=3|pages=366–380|jstor=24460821|issn=0011-1953}}</ref> Religion has taken on many forms that vary by culture and individual perspective in alignment with the geographic, social, and linguistic diversity of the planet.<ref name=":5" /> Religion can include a belief in life after death (commonly involving belief in an [[afterlife]]),<ref>{{cite journal| vauthors = Walker GC |date=2000-08-01|title=Secular Eschatology: Beliefs about Afterlife |journal=OMEGA - Journal of Death and Dying|language=en|volume=41|issue=1|pages=5–22|doi=10.2190/Q21C-5VED-GYW6-W091|s2cid=145686249|issn=0030-2228}}</ref> the [[origin of life]],<ref>{{cite journal| vauthors = Bautista JS, Herrera VE, Miranda RC |date=2017|title=Scientific and Religious Beliefs about the Origin of Life and Life after Death: Validation of a Scale|url=https://www.hrpub.org/journals/article_info.php?aid=5989|journal=Universal Journal of Educational Research|language=en|volume=5|issue=6|pages=995–1007|doi=10.13189/ujer.2017.050612|issn=2332-3205}}</ref> the nature of the [[universe]] ([[religious cosmology]]) and its [[ultimate fate]] ([[eschatology]]), and what is [[morality|moral]] or immoral.<ref>{{cite journal | vauthors = McKay R, Whitehouse H | title = Religion and morality | journal = Psychological Bulletin | volume = 141 | issue = 2 | pages = 447–73 | date = March 2015 | pmid = 25528346 | pmc = 4345965 | doi = 10.1037/a0038455 }}</ref> A common source for answers to these questions are beliefs in [[transcendence (religion)|transcendent]] divine beings such as [[deities]] or a singular [[God]], although not all religions are [[theistic]].<ref>{{cite web|title=Summary of Religions and Beliefs|url=https://www.bolton.ac.uk/Chaplaincy/Worldviews/Summary.aspx#gsc.tab=0|access-date=2020-10-08|website=www.bolton.ac.uk}}</ref><ref>{{cite journal| vauthors = Ball P |title=Complex societies evolved without belief in all-powerful deity|url=https://www.nature.com/news/complex-societies-evolved-without-belief-in-all-powerful-deity-1.17040|journal=Nature News|year=2015|language=en|doi=10.1038/nature.2015.17040|s2cid=183474917}}</ref>

Although the exact level of religiosity can be hard to measure,<ref name="Hall2008">{{cite journal | vauthors = Hall DE, Meador KG, Koenig HG | title = Measuring religiousness in health research: review and critique | journal = Journal of Religion and Health | volume = 47 | issue = 2 | pages = 134–63 | date = June 2008 | pmid = 19105008 | doi = 10.1007/s10943-008-9165-2 | pmc = 8823950 | type = Submitted manuscript | s2cid = 25349208 | url = https://zenodo.org/record/1232820 }}</ref> a majority of humans profess some variety of religious or spiritual belief.<ref>{{cite news| vauthors = Sherwood H |date=2018-08-27|title=Religion: why faith is becoming more and more popular|language=en-GB|work=The Guardian|url=https://www.theguardian.com/news/2018/aug/27/religion-why-is-faith-growing-and-what-happens-next|access-date=2020-10-08|issn=0261-3077}}</ref> In 2015 the plurality were [[Christians|Christian]] followed by [[Muslims]], [[Hindus]] and [[Buddhism|Buddhists]].<ref>{{cite web| vauthors = Hackett C, McClendon D |date=2017|title=Christians remain world's largest religious group, but they are declining in Europe|url=https://www.pewresearch.org/fact-tank/2017/04/05/christians-remain-worlds-largest-religious-group-but-they-are-declining-in-europe/|access-date=2020-10-08|website=Pew Research Center|language=en-US}}</ref> As of 2015, about 16%, or slightly under 1.2 billion humans, were [[irreligious]], including those with no religious beliefs or no identity with any religion.<ref>{{cite web|date=2017-04-05|title=The Changing Global Religious Landscape|url=https://www.pewforum.org/2017/04/05/the-changing-global-religious-landscape/|access-date=2020-10-08|website=Pew Research Center's Religion & Public Life Project|language=en-US}}</ref>

=== Science and philosophy ===

{{Main|Science|Philosophy}}

[[File:Dunhuang star map.jpg|thumb|right|The [[Dunhuang map]], a [[star map]] showing the North Polar region. China circa 700.]]

An aspect unique to humans is their ability to [[Knowledge transfer|transmit knowledge]] from one generation to the next and to continually build on this information to develop tools, [[scientific law]]s and other advances to pass on further.<ref>{{cite web| vauthors = Di Christina M |title=A Very Human Story: Why Our Species Is Special|url=https://www.scientificamerican.com/article/a-very-human-story-why-our-species-is-special/|access-date=2020-09-27|website=Scientific American|language=en}}</ref> This accumulated knowledge can be tested to answer questions or make predictions about how the universe functions and has been very successful in advancing human ascendancy.<ref>{{cite encyclopedia | vauthors = Andersen H, Hepburn B |title=Scientific Method|date=2020|url=https://plato.stanford.edu/archives/win2020/entries/scientific-method/|encyclopedia=The Stanford Encyclopedia of Philosophy| veditors = Zalta EN |edition=Winter 2020|publisher=Metaphysics Research Lab, Stanford University|access-date=2020-10-08}}</ref> [[Aristotle]] has been described as the first scientist,<ref>{{Cite journal| vauthors = Lo Presti R | date=2014|title=History of science: The first scientist|url=https://www.nature.com/articles/512250a|journal=Nature|language=en|volume=512|issue=7514|pages=250–251|doi=10.1038/512250a| bibcode=2014Natur.512..250L| s2cid=4394696|issn=1476-4687}}</ref> and preceded the rise of scientific thought through the [[Hellenistic period]].<ref>{{Cite book| vauthors = Russo L | url=https://www.worldcat.org/oclc/883392276|title=The forgotten revolution : how science was born in 300 BC and why it had to be reborn|date=2004|isbn=978-3-642-18904-3|location=Berlin|page=1|oclc=883392276}}</ref> Other early advances in science came from the [[Science and technology of the Han dynasty|Han Dynasty]] in China and during the [[Islamic Golden Age]].<ref>{{Cite book| vauthors = Needham J, Wang L |url=https://www.worldcat.org/oclc/779676|title=Science and civilisation in China|year=1954|isbn=0-521-05799-X|location=Cambridge [England]|page=111|oclc=779676|author-link=Joseph Needham}}</ref><ref name=":15" /> The [[Scientific Revolution|scientific revolution]], near the end of the [[Renaissance]], led to the emergence of [[modern science]].<ref>{{Cite book| vauthors = Henry J | url=https://www.worldcat.org/oclc/615209781|title=The scientific revolution and the origins of modern science|publisher=Palgrave Macmillan|year=2008|isbn=978-1-137-07904-6|edition=3|location=Houndsmills, Basingstoke, Hampshire|chapter=Renaissance and Revolution|oclc=615209781}}</ref>

A chain of events and influences led to the development of the [[scientific method]], a process of observation and experimentation that is used to differentiate science from [[pseudoscience]].<ref>{{cite web | vauthors = Hansson SO | veditors = Zalta EN |year=2017|title=Science and Pseudo-Science|url=https://plato.stanford.edu/entries/pseudo-science/|url-status=live|archive-url=https://web.archive.org/web/20170611061811/https://plato.stanford.edu/entries/pseudo-science/|archive-date=11 June 2017|access-date=3 July 2017|website=Stanford Encyclopedia of Philosophy|publisher=Metaphysics Research Lab, Stanford University}}</ref> An understanding of [[mathematics]] is unique to humans, although other species of animals have some [[numerical cognition]].<ref>{{cite book | vauthors = Olmstead MC, Kuhlmeier VA | title = Comparative Cognition | publisher = Cambridge University Press | date = 2015 | pages = 209–10 | isbn = 978-1-107-01116-8 }}</ref> All of science can be divided into three major branches, the [[formal sciences]] (e.g., [[logic]] and [[mathematics]]), which are concerned with [[formal systems]], the [[applied sciences]] (e.g., engineering, medicine), which are focused on practical applications, and the empirical sciences, which are based on [[empirical observation]] and are in turn divided into [[natural sciences]] (e.g., [[physics]], [[chemistry]], [[biology]]) and [[social sciences]] (e.g., [[psychology]], economics, sociology).<ref>{{cite web|title=Branches of Science|url=https://pmr.uchicago.edu/sites/pmr.uchicago.edu/files/uploads/BranchesofSciencePresentation.pdf|url-status=dead|archive-url=https://web.archive.org/web/20170423062909/https://pmr.uchicago.edu/sites/pmr.uchicago.edu/files/uploads/BranchesofSciencePresentation.pdf|archive-date=23 April 2017|access-date=26 June 2017|publisher=[[University of Chicago]]}}</ref>

Philosophy is a field of study where humans seek to understand fundamental truths about themselves and the world in which they live.<ref>{{cite web|title=What is Philosophy? | work = Department of Philosophy | publisher = Florida State University |url= https://philosophy.fsu.edu/undergraduate-study/why-philosophy/What-is-Philosophy|access-date=8 October 2020 }}</ref> Philosophical inquiry has been a major feature in the development of humans' intellectual history.<ref>{{cite encyclopedia|title=Philosophy | encyclopedia = Definition, Systems, Fields, Schools, & Biographies | publisher = Encyclopedia Britannica |url=https://www.britannica.com/topic/philosophy|access-date=8 October 2020 }}</ref> It has been described as the "no man's land" between definitive scientific knowledge and dogmatic religious teachings.<ref>{{cite journal| vauthors = Kaufmann F, Russell B |date=1947|title=A History of Western Philosophy and its Connection with Political and Social Circumstances from the Earliest Times to the Present Day.|url=https://www.jstor.org/stable/2102800|journal=Philosophy and Phenomenological Research|volume=7|issue=3|page=461|doi=10.2307/2102800|jstor=2102800}}</ref> Philosophy relies on reason and evidence, unlike religion, but does not require the empirical observations and experiments provided by science.<ref>{{cite web | vauthors = Messerly JG | date = 25 March 2016 |title=What is the Difference Between Philosophy, Science, and Religion?|url=https://ieet.org/index.php/IEET2/more/messerly20160325|access-date= 8 August 2020 |website=ieet.org}}</ref> Major fields of philosophy include [[metaphysics]], [[epistemology]], [[Logic (philosophy)|logic]], and [[axiology]] (which includes [[ethics]] and [[aesthetics]]).<ref>{{cite journal| vauthors = Hassan NR, Mingers J, Stahl B |date=2018-05-04|title=Philosophy and information systems: where are we and where should we go? |journal=European Journal of Information Systems | volume=27|issue=3|pages=263–277|doi=10.1080/0960085X.2018.1470776|s2cid=64796132|issn=0960-085X}}</ref>

 

[[File:Indian family in Brazil posed in front of hut.jpg|thumb|upright|Humans often live in family-based social structures.]]

Society is the system of organizations and institutions arising from interaction between humans. Humans are highly social and tend to live in large complex social groups. They can be divided into different groups according to their income, wealth, [[power (social and political)|power]], [[reputation]] and other factors. The structure of [[social stratification]] and the degree of [[social mobility]] differs, especially between modern and traditional societies.<ref name=":1">{{cite web |title=Social Stratification |url=https://web.unitn.it/files/download/8481/srs_schizzerotto_social_stratification_2_as.pdf |url-status=dead |archive-url=https://web.archive.org/web/20180320150018/https://web.unitn.it/files/download/8481/srs_schizzerotto_social_stratification_2_as.pdf |archive-date=20 March 2018 |access-date=3 July 2017 |publisher=[[University of Trento]] |vauthors=Schizzerotto A}}</ref>{{Unreliable source?|date=June 2022}} Human groups range from the size of [[Family|families]] to nations. The first form of human social organization is thought to have resembled [[hunter-gatherer]] [[Band society|band societies]].<ref>{{cite book| vauthors = Fukuyama F |title=The origins of political order : from prehuman times to the French Revolution|date=2012|publisher=Farrar, Straus and Giroux|isbn=978-0-374-53322-9|page=53|oclc=1082411117}}</ref>{{Better source needed|reason=The current source is insufficiently reliable ([[WP:NOTRS]]).|date=June 2022}}

 

{{main|Gender|}}

 

Human societies typically exhibit [[Gender role|gender roles]] that distinguish between [[Masculinity|masculine]] and [[Femininity|feminine]] characteristics and prescribe the range of acceptable behaviours and attitudes for their members based on their [[sex]].<ref>{{Citation |title=Social Role Theory of Sex Differences and Similarities : A Current Appraisal |date=2000 |url=https://www.taylorfrancis.com/chapters/edit/10.4324/9781410605245-12/social-role-theory-sex-differences-similarities-current-appraisal |work=The Developmental Social Psychology of Gender |pages=137–188 |publisher=Psychology Press |doi=10.4324/9781410605245-12 |isbn=978-1-4106-0524-5 |access-date=2022-06-10}}</ref><ref>{{Cite encyclopedia |year=2003 |title=Gender Roles and Society |encyclopedia=Human Ecology: An Encyclopedia of Children, Families, Communities, and Environments |publisher=ABC-CLIO |location=Santa barbara, CA |url=https://digitalcommons.library.umaine.edu/soc_facpub/1/ |last=Blackstone |first=Amy |editor-last=Miller |editor-first=Julia R. |editor2-last=Lerner |editor2-first=Richard M. |editor3-last=Schiamberg |editor3-first=Lawrence B. }}</ref> The most common categorisation is a [[gender binary]] of [[men]] and [[women]].<ref name="Nadal-re-binary">Kevin L. Nadal, ''The SAGE Encyclopedia of Psychology and Gender'' (2017, {{ISBN|1483384276}}), page 401: "Most cultures currently construct their societies based on the understanding of gender binary—the two gender categorizations (male and female). Such societies divide their population based on biological sex assigned to individuals at birth to begin the process of gender socialization."</ref> Many societies recognise a [[third gender]],<ref>{{Cite book |last=Herdt |first=Gilbert |url=https://books.google.com/books?id=8nf8DwAAQBAJ |title=Third Sex, Third Gender: Beyond Sexual Dimorphism in Culture and History |publisher=Princeton University Press |year=2020 |isbn=978-1-942130-52-9 |location=Princeton, NJ |pages=21–83 |language=en |chapter=Third Sexes and Third Genders}}</ref> or less commonly a fourth or fifth.<ref>Trumbach, Randolph (1994). ''London's Sapphists: From Three Sexes to Four Genders in the Making of Modern Culture.'' In Third Sex, Third Gender: Beyond Sexual Dimorphism in Culture and History, edited by Gilbert Herdt, 111-36. New York: Zone (MIT). {{ISBN|978-0-942299-82-3}}</ref><ref name="Graham">Graham, Sharyn (2001), [http://www.insideindonesia.org/weekly-articles/sulawesis-fifth-gender Sulawesi's fifth gender], [[Inside Indonesia]], April–June 2001.</ref> In some other societies, [[Non-binary gender|non-binary]] is used as an umbrella term for a range of [[Gender identity|gender identities]] that are not solely male or female.<ref name="richardsetal">{{Cite journal |last1=Richards |first1=Christina |last2=Bouman |first2=Walter Pierre |last3=Seal |first3=Leighton |last4=Barker |first4=Meg John |last5=Nieder |first5=Timo O. |last6=T'Sjoen |first6=Guy |date=2016 |title=Non-binary or genderqueer genders |url=https://biblio.ugent.be/publication/7279758 |url-status=live |journal=International Review of Psychiatry |volume=28 |issue=1 |pages=95–102 |doi=10.3109/09540261.2015.1106446 |pmid=26753630 |archive-url=https://web.archive.org/web/20190626224658/https://biblio.ugent.be/publication/7279758 |archive-date=26 June 2019 |access-date=9 June 2019 |hdl-access=free |s2cid=29985722 |hdl=1854/LU-7279758}}</ref>

 

 

 

 

 

 

 

 

 

 

 

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{{Apes}}

{{Sister bar|Humans|species=Homo sapiens|commons=Homo sapiens|commonscat=yes|v=no|n=no|q=People|b=no}}

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