Human

=== Sexuality and love ===
{{Main|Human sexuality|Love}}
[[File:Sweet Baby Kisses Family Love.jpg|thumb|Human parents often display [[familial love]] for their children.]]
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={{GBurl|id=8iarCwAAQBAJ|p=4}}|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={{GBurl|id=qrPHYok19v8C|p=32}}|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={{GBurl|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|access-date=30 July 2022}}</ref><ref name="Balthazart">{{cite book|vauthors=Balthazart J|url={{GBurl|id=3fjGjlcVINkC}}|title=The Biology of Homosexuality|date=2012|publisher=Oxford University Press|isbn=978-0-19-983882-0|pages=13–14|access-date=30 July 2022}}</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 |publisher=Basic Books |isbn=978-0-465-00802-5 |url=https://archive.org/details/evolutionofdesir00buss }}</ref>

Love most commonly refers to a feeling of strong attraction or emotional [[Attachment (psychology)|attachment]]. It can be impersonal (the love of an object, ideal, or strong political or spiritual connection) or interpersonal (love between humans).<ref name="Fromm, Erich 2000">{{cite book | vauthors = Fromm E |title=The art of loving |date=2000 |publisher= Harper Perennial |location=New York |isbn=978-0-06-095828-2}}</ref> When in love [[dopamine]], [[norepinephrine]], [[serotonin]] and other chemicals stimulate the brain's [[pleasure center]], leading to side effects such as increased [[heart rate]], loss of [[Anorexia (symptom)|appetite]] and [[Insomnia|sleep]], and an [[Euphoria|intense feeling of excitement]].<ref>{{cite web|date=14 February 2017|title=Love, Actually: The science behind lust, attraction, and companionship|url=https://sitn.hms.harvard.edu/flash/2017/love-actually-science-behind-lust-attraction-companionship/|access-date=25 October 2020|website=Science in the News|language=en-US|archive-date=28 October 2020|archive-url=https://web.archive.org/web/20201028090542/http://sitn.hms.harvard.edu/flash/2017/love-actually-science-behind-lust-attraction-companionship/|url-status=live}}</ref>