Human

=== Consciousness and thought ===
{{Main|Consciousness|Cognition}}
Human consciousness, at its simplest, is [[sentience]] or [[awareness]] of internal or external existence.<ref name="consciousness">{{cite encyclopedia|title=Consciousness|dictionary=Merriam-Webster|access-date=4 June 2012|url=https://www.merriam-webster.com/dictionary/consciousness|archive-date=7 September 2019|archive-url=https://web.archive.org/web/20190907122314/https://www.merriam-webster.com/dictionary/consciousness|url-status=live}}</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|access-date=30 July 2022|archive-date=14 October 2019|archive-url=https://web.archive.org/web/20191014065308/https://plato.stanford.edu/entries/consciousness/|url-status=live}}</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 = 227–247 | doi = 10.1017/S0140525X00038474 | s2cid = 246244859 | doi-access = free }}</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 = 717–731 | 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 August 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|archive-date=13 April 2021|archive-url=https://web.archive.org/web/20210413163246/https://plato.stanford.edu/entries/consciousness-higher/|url-status=live}}</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]]|archive-date=8 July 2016|archive-url=https://web.archive.org/web/20160708041349/http://www.oxforddictionaries.com/definition/english/cognition|url-status=dead}}</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 | title = Information—Consciousness—Reality| chapter = The Consciousness of Reality|date=2019 |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=13 August 2014|publisher=Apa.org|archive-date=8 July 2014|archive-url=https://web.archive.org/web/20140708064652/http://www.apa.org/research/action/glossary.aspx|url-status=live}}</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=9 July 2014|access-date=28 August 2017|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 }}</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=1 January 2004|title=Intelligence Assessment |journal=Encyclopedia of Applied Psychology|language=en|pages=307–314|doi=10.1016/B0-12-657410-3/00510-9|isbn=978-0-12-657410-4}}</ref>