Editing Biology and sexual orientation (section)

===Kin selection===
{{See also|Altruism (biology)|l1=Biological altruism|Inclusive fitness in humans}}

The "gay uncle hypothesis" posits that people who themselves do not have children may nonetheless increase the prevalence of their family's genes in future generations by providing resources (e.g., food, supervision, defense, shelter) to the offspring of their closest relatives.<ref name="Moskowitz_2010">{{cite web | date = 11 February 2010 | vauthors = Moskowitz C |title=How Gay Uncles Pass Down Genes |url=https://www.livescience.com/6106-gay-uncles-pass-genes.html |website=livescience.com |access-date=22 July 2020 |language=en}}</ref>

This hypothesis is an extension of the theory of kin selection, which was originally developed to explain apparent altruistic acts which seemed to be maladaptive. The initial concept was suggested by [[J. B. S. Haldane]] in 1932 and later elaborated by many others including [[John Maynard Smith]], [[W. D. Hamilton]], [[Mary Jane West-Eberhard]], and [[E. O. Wilson]].<ref name="Mayr_1982">{{cite book | vauthors = Mayr E |title=The growth of biological thought : diversity, evolution, and inheritance |date=1982 |publisher=Belknap Press |location=Cambridge, Mass. |isbn=978-0-674-36446-2 | page = [https://books.google.com/books?id=pHThtE2R0UQC&lpg=PA1061 598] }}</ref><ref>{{cite book|last=Wilson|first=Edward O.|year=1975|title=Sociobiology: The New Synthesis|title-link=Sociobiology: The New Synthesis|place=Cambridge, MA|publisher=Belknap Press|page=279|isbn=978-0674816213}}</ref> This concept was also used to explain the patterns of certain social insects where most of the members are non-reproductive. Conversely, social psychologist [[David Buss]] has argued that there is no empirical evidence that supports the hypothesis.<ref>{{cite book|last=Buss|first=David|year=2016|orig-year=1994|title=The Evolution of Desire: Strategies of Human Mating|title-link=The Evolution of Desire|place=New York|publisher=Basic Books|edition=3rd|page=97|isbn=978-0465097760}}</ref>

In 2001, ''[[Evolution and Human Behavior]]'' published a questionnaire survey of 57 heterosexual and 66 homosexual male subjects in the [[United States]] that found that homosexual subjects were no more likely to provide financial resources towards family members, heterosexual subjects were more likely give more financial resources to siblings than homosexual subjects, and homosexual subjects tended to be more estranged from family members.<ref>{{cite journal|last1=Bobrow|first1=David|last2=Bailey|first2=J. Michael|author-link2=J. Michael Bailey|year=2001|title=Is male homosexuality maintained via kin selection?|journal=Evolution and Human Behavior|publisher=Elsevier|volume=22|issue=5|pages=361–368|doi=10.1016/S1090-5138(01)00074-5|bibcode=2001EHumB..22..361B }}</ref> In 2005, ''[[Archives of Sexual Behavior]]'' published a replication study with 60 heterosexual and 60 homosexual male subjects in [[England]] that likewise found no significant differences between heterosexual and homosexual subjects in familial affinity or generosity towards family members.<ref>{{cite journal|last1=Rahman|first1=Qazi|last2=Hull|first2=Matthew S.|year=2005|title=An Empirical Test of the Kin Selection Hypothesis for Male Homosexuality|journal=Archives of Sexual Behavior|publisher=Springer Science+Business Media|volume=34|issue=4 |pages=461–467|doi=10.1007/s10508-005-4345-6|pmid=16010468 }}</ref> Vasey, Pocock, and VanderLaan (2007) and Vasey and VanderLaan (2010) tested the theory on the Pacific island of [[Samoa]], where they studied women, straight men, and the ''[[Faʻafafine|fa'afafine]]'', men who prefer other men as sexual partners and are accepted within the culture as a distinct third gender category. Vasey and VanderLaan found that the ''fa'afafine'' said they were significantly more willing to help kin, yet much less interested in helping children who are not family, providing the first evidence to support the kin selection hypothesis. The hypothesis is consistent with other studies on homosexuality, which show that it is more prevalent amongst both siblings and twins.<ref>{{cite journal|last1=Vasey|first1=Paul L.|last2=Pocock|first2=David S.|last3=VanderLaan|first3=Doug P.|year=2007|title=Kin selection and male androphilia in Samoan ''fa'afafine''|journal=Evolution and Human Behavior|publisher=Elsevier|volume=28|issue=3|pages=159–167|doi=10.1016/j.evolhumbehav.2006.08.004|bibcode=2007EHumB..28..159V }}</ref><ref name="VanderLaan_2011">{{cite thesis | url=https://www.uleth.ca/dspace/handle/10133/3159 | title=The development and evolution of male androphilia in Samoan fa'afafine| year=2011| degree = Ph.D. | vauthors = VanderLaan DP }}</ref><ref name="Vasey_2010">{{cite journal | vauthors = Vasey PL, VanderLaan DP | title = An adaptive cognitive dissociation between willingness to help kin and nonkin in Samoan Fa'afafine | journal = Psychological Science | volume = 21 | issue = 2 | pages = 292–7 | date = February 2010 | pmid = 20424059 | doi = 10.1177/0956797609359623 | s2cid = 16265819 }}; {{Lay source | vauthors =  Bolcer J | date = 5 February 2010 | url= http://www.advocate.com/news/daily-news/2010/02/05/study-supports-gay-super-uncles-theory | title=Study Supports Gay Super Uncles Theory | work = The Advocate }}</ref>

Anthropologist Raymond Hames notes that Vasey and VanderLaan's research on the ''fa'afafine'' identifies them as "transgendered androphilic males" as opposed to "sex-gender congruent androphiles" or "egalitarian homosexuals" in Western societies.<ref>{{cite book|last=Hames|first=Raymond|editor-last=Buss|editor-first=David M.|year=2016|orig-year=2005|chapter=19. Kin Selection|title=The Handbook of Evolutionary Psychology, Volume 1: Foundations|place=Hoboken, NJ|publisher=Wiley|edition=2nd|pages=512|isbn=978-1118755884}}</ref> Based on research conducted in [[Japan]] that found no evidence that homosexual Japanese men exhibited elevated avuncular tendencies compared to heterosexual counterparts, Vasey and VanderLaan (2011) provides evidence that if an adaptively designed avuncular male androphilic phenotype exists and its development is contingent on a particular social environment, then a collectivistic cultural context is insufficient, in and of itself, for the expression of such a phenotype.<ref>{{cite journal | vauthors = Vasey PL, VanderLaan DP | title = Sexual orientation in men and avuncularity in Japan: implications for the kin selection hypothesis | url = https://archive.org/details/sim_archives-of-sexual-behavior_2012-02_41_1/page/209 | journal = Archives of Sexual Behavior | volume = 41 | issue = 1 | pages = 209–15 | date = February 2012 | pmid = 21656333 | doi = 10.1007/s10508-011-9763-z | s2cid = 33348533 }}</ref> In 2011 and 2014, the ''Journal of Cognition and Culture'' published two studies that found that [[Canada|Canadian]] homosexual men exhibited significantly greater altruistic tendencies toward kin versus non-kin children relative to heterosexual men and women, but did not find that Canadian homosexual males exhibited significantly higher altruistic behavior towards nieces and nephews over geographic disconnect.<ref>{{cite journal|last1=Forrester|first1=Deanna L.|last2=VanderLaan|first2=Doug P.|last3=Parker|first3=Jessica L.|last4=Vasey|first4=Paul L.|year=2011|title=Male Sexual Orientation and Avuncularity in Canada: Implications for the Kin Selection Hypothesis|journal=Journal of Cognition and Culture|publisher=Brill|volume=11|issue=3–4|pages=339–352|doi=10.1163/156853711X591288}}</ref><ref>{{cite journal|last1=Abild|first1=Miranda L.|last2=VanderLaan|first2=Doug P.|last3=Vasey|first3=Paul L.|year=2014|title=Does Geographic Proximity Influence the Expression of Avuncular Tendencies in Canadian Androphilic Males?|journal=Journal of Cognition and Culture|publisher=Brill|volume=14|issue=1–2|pages=41–63|doi=10.1163/15685373-12342109}}</ref>

In 2016, the ''[[Journal of Sex Research]]'' published a study comprising 278 homosexual (or ''[[kathoey]]'') and heterosexual male subjects in [[Italy]] and [[Spain]] and from the [[Urak Lawoi]] of [[Thailand]] that found no greater kin altruism or avuncularity among homosexual subjects in any of the three cultures and that kin altruism and avuncularity was associated with societal differences in cultural norms about general altruism toward non-kin children.<ref>{{cite journal|last1=Camperio Ciani|first1=Andrea|last2=Battaglia|first2=Umberto|last3=Liotta|first3=Marina|year=2016|title=Societal Norms Rather Than Sexual Orientation Influence Kin Altruism and Avuncularity in Tribal Urak-Lawoi, Italian, and Spanish Adult Males|journal=Journal of Sex Research|publisher=Routledge|volume=53|issue=2|pages=137–148|doi=10.1080/00224499.2014.993748|pmid=26132515}}</ref> In 2017, ''Evolutionary Psychological Science'' published a [[logistic regression]] analysis of the results of 17,295 female subjects across 58 countries on [[World Values Survey]] questionnaires about attitudes toward homosexuality that found that subjects that were potentially most in need of [[Alloparenting|alloparental]] support exhibited significantly more positive attitudes towards homosexuals, which the researchers suggested was circumstantial evidence in support of the hypothesis on a global scale.<ref>{{cite journal|last1=Playà|first1=Eduard|last2=Vinicius|first2=Lucio|last3=Vasey|first3=Paul L.|year=2017|title=Need for Alloparental Care and Attitudes Toward Homosexuals in 58 Countries: Implications for the Kin Selection Hypothesis|journal=Evolutionary Psychological Science|publisher=Springer|volume=3|issue=4 |pages=345–352|doi=10.1007/s40806-017-0105-9|doi-access=free}}</ref> In 2018, ''Archives of Sexual Behavior'' published a study comparing avuncular tendencies between heterosexual and homosexual men on [[Java]] in [[Indonesia]] that found that homosexual men reported an increased willingness to transfer resources and money toward nephews and nieces but only reduced the direct reproductive cost to homosexual men by 20%, with the researchers concluding that kin selection alone was an insufficient explanation of male homosexuality.<ref>{{cite journal|last1=Nila|first1=Sarah|last2=Barthes|first2=Julien|last3=Crochet|first3=Pierre-Andre|last4=Suryobroto|first4=Bambang|last5=Raymond|first5=Michel|year=2018|title=Kin Selection and Male Homosexual Preference in Indonesia|journal=Archives of Sexual Behavior|publisher=Springer|volume=47|issue=8 |pages=2455–2465|doi=10.1007/s10508-018-1202-y|pmid=29797146 |url=https://hal.umontpellier.fr/hal-01827409/file/2018_Nila_Kin%20selection%20and%20male%20homosexual%20preference%20in%20Indonesia.pdf }}</ref>