Editing Polygamy (section)

==Scientific and prehistorical perspectives==
Scientific studies classify humans as "mildly polygynous" or "monogamous with polygynous tendencies."<ref name="pmid19403194" /><ref name="Frost" /><ref name="Low" /><ref name="Scheidel" /> As mentioned above, data from 1960 to 1980 in the [[Human Relations Area Files|''Ethnographic Atlas Codebook'']] indicated that polygamy was common.<ref>Murdock GP (1981) ''Atlas of World Cultures''. Pittsburgh, PA: University of Pittsburgh Press</ref> A separate 1988 review examined the practices of 849 societies from before Western imperialism and colonization. The review found that 708 of the societies (83%) accepted polygyny. Only 16% were monogamous and 1% polyandrous.<ref name="Rethinking">{{cite news |last1=White |first1=Douglas |last2=Betzig |first2=Laura |author-link2=Laura Betzig|last3=Mulder |first3=Monique |url=https://www.jstor.org/stable/2743506 |title=Rethinking Polygyny: Co-Wives, Codes, and Cultural Systems [and Comments and Reply] |work=Current Anthropology |date=1988-08-01 |jstor=2743506 |accessdate=2023-06-28 |archive-date=28 June 2023 |archive-url=https://web.archive.org/web/20230628222332/https://www.jstor.org/stable/2743506 |url-status=live }}</ref> Subsequent evidence in 2012 found that polyandry (in which women have multiple male partners) was likely in pre-history; it also identified 53 communities studied between 1912 and 2010 with either formal or informal polyandry, indicating that polyandry was more common worldwide than previously believed. The authors found that polyandry was most common in egalitarian societies, and suspected contributors to polyandry included fewer men (due to the existence or threat of high adult male mortality or absence/travel) and higher male contributions towards food production.<ref name="Starkweather2012" /> Polyandry still appears to occur in the minority of societies. Regardless of the type of polygamy, even when polygyny is accepted in the community, the majority of relationships in the society are monogamous in practice – while couples remain in the relationship, which may not be lifelong.<ref name="Schacht" /> In many historical communities, serial monogamy may have been the accepted practice rather than a lifelong monogamous bond. How monogamy is defined when it comes to accepted sexual activity outside of the relationship, however, may differ by society.<ref name="Schacht" />

Recent anthropological data suggest that the modern concept of life-long monogamy has been in place for only the last 1,000 years.<ref>{{cite news |last=Zimmer |first=Carl |url=https://www.nytimes.com/2013/08/02/science/monogamys-boost-to-human-evolution.html |title=Monogamy and Human Evolution |work=The New York Times |location=New York |date=2013-08-02 |accessdate=2023-06-28 |archive-date=28 June 2023 |archive-url=https://web.archive.org/web/20230628222331/https://www.nytimes.com/2013/08/02/science/monogamys-boost-to-human-evolution.html |url-status=live }}</ref> Genetic evidence has demonstrated that a greater proportion of men began contributing to the genetic pool between 5,000 and 10,000 years ago, which suggests that reproductive monogamy became more common at that time.<ref name="pmid12962309" /> This would correspond to the Neolithic agricultural revolution. During this time, formerly nomadic societies began to claim and settle land for farming, leading to the advent of property ownership and therefore inheritance. Men would therefore seek to ensure that their land would go to direct descendants and had a vested interest in limiting the sexual activities of their reproductive partners. It is possible that the concept of marriage and permanent monogamy evolved at this time.<ref name="Goody">{{cite book |last1=Goody |first1=Jack |title=Production and Reproduction: A Comparative Study of the Domestic Domain |location=Cambridge |publisher=Cambridge University Press |year=1976}}</ref>

Other scientific arguments for monogamy prior to 2003 were based on characteristics of reproductive physiology, such as sperm competition,<ref>{{cite journal | last1 = Anderson | first1 = M. J. | last2 = Dixson | first2 = A. F. | year = 2002 | title = Sperm competition: motility and the midpiece in primates | journal = Nature | volume = 416 | issue = 6880 | page = 496 | doi=10.1038/416496a | pmid = 11932733 | bibcode = 2002Natur.416..496A | s2cid = 4388134 | doi-access = free }}</ref> sexual selection in primates,<ref>{{cite journal | last1 = Dixson | first1 = A. L. | last2 = Anderson | first2 = M. J. | year = 2002 | title = Sexual selection, seminal coagulation and copulatory plug formation in primates | journal = Folia Primatol | volume = 73 | issue = 2–3 | pages = 63–69 | doi= 10.1159/000064784| pmid = 12207054 | s2cid = 46804812 }}</ref> and body size characteristics.<ref>{{cite journal | last1 = Harcourt | first1 = A. H. | last2 = Harvey | first2 = P. H. | last3 = Larson | first3 = S. G. | last4 = Short | first4 = RV | year = 1981 | title = Testis weight, body weight and breeding system in primates | journal = Nature | volume = 293 | issue = 5827 | pages = 55–57 | doi= 10.1038/293055a0 | pmid = 7266658 | bibcode = 1981Natur.293...55H | s2cid = 22902112}}</ref> A 2019 synthesis of these and other data found that the weight of the evidence supports a mating bond that may include polygyny or polyandry, but is most likely to be predominantly serial monogamy.<ref name="Schacht" />

More recent genetic data has clarified that, in most regions throughout history, a smaller proportion of men contributed to human genetic history compared to women.<ref name="pmid12962309" /><ref name="pmid15317874">{{cite journal| last1=Wilder |first1=Jason | last2=Mobasher |first2=Zahra | last3=Hammer | first3=Michael| title=Genetic evidence for unequal effective population sizes of human females and males. | journal=Mol Biol Evol | year= 2004 | volume= 21 | issue= 11 | pages= 2047–57 | pmid=15317874 | doi=10.1093/molbev/msh214 | pmc= | doi-access=free }}</ref> Assuming an equal number of men and women are born and survive to reproduce, this would indicate that historically, only a subset of men fathered children and did so with multiple women (and may suggest that many men either did not procreate or did not have children that survived to create modern ancestors). This circumstance could occur for several reasons, but there are three common interpretations:
# The first interpretation is a harem model, where one man will out-compete other men (presumably through acts of violence or power) for exclusive sexual access to a group of women. Groups of women could be related or unrelated. This does not seem to reflect real-world observations in more modern polygyny societies, where the majority of individuals seldom have more than one partner at a time.<ref name="Schacht" />
# Second, it may suggest that some men had either more sex or more reproductive success with multiple women simultaneously; this could be caused by sexual liaisons outside of a lifelong "monogamous" relationship (which may or may not be acceptable in their society), having multiple committed partners at once (polygyny), or simply sexual reproduction with multiple partners entirely outside of committed relationships (i.e., casual sex without relationships or pair-bonding).
# Third, it may suggest that some men were more likely than other men to have a series of monogamous relationships that led to children with different women throughout the man's life (serial monogamy).<ref name="Schacht" /> There are a variety of explanations for this that range from the woman's decisions (the man's perceived attractiveness or ability to produce food) to the man's (social or coercive power).

The serial monogamy interpretation of genetic history would be congruent with other findings, such as the fact that humans form pair bonds (although not necessarily for life) and that human fathers invest in at least the early upbringing of their children.<ref name="Schacht" /> Serial monogamy would also be consistent with the existence of a "honeymoon period", a period of intense interest in a single sexual partner (with less interest in other women) which may help to keep men invested in staying with the mother of their child for this period.<ref>{{cite journal |last1=Fletcher |first1=Garth |last2=Simpson |first2=Jeffry |last3=Campbell |first3=Lorne |last4=Overall |first4=Nickola |author-link4=Nickola Overall |date=2015-01-01 |title=Pair-Bonding, Romantic Love, and Evolution: The Curious Case of "Homo sapiens" |url=https://www.jstor.org/stable/44281912 |url-status=live |journal=Perspectives on Psychological Science |volume=10 |issue=1 |pages=20–36 |doi=10.1177/1745691614561683 |jstor=44281912 |pmid=25910380 |s2cid=16530399 |archive-url=https://web.archive.org/web/20230628222331/https://www.jstor.org/stable/44281912 |archive-date=28 June 2023 |accessdate=2023-06-28}}</ref> When reciprocated, this "honeymoon period" lasts 18 months to three years in most cases.<ref name="Love and Limerence">{{cite book |last=Tennov |first=Dorothy |author-link=Dorothy Tennov |title=Love and Limerence: the Experience of Being in Love |url=https://books.google.com/books?id=uPsDAAAACAAJ |access-date=12 March 2011 |year=1999 |publisher=Scarborough House |isbn=978-0-8128-6286-7 |archive-date=27 March 2023 |archive-url=https://web.archive.org/web/20230327220413/https://books.google.com/books?id=uPsDAAAACAAJ |url-status=live }}</ref><ref>{{cite book|last1=Leggett|first1=John C.|last2=Malm|first2=Suzanne|title=The Eighteen Stages of Love: Its Natural History, Fragrance, Celebration and Chase|url=https://books.google.com/books?id=2g0RPVk7i1QC&pg=PA27|access-date=12 March 2011|date=March 1995|publisher=Rowman & Littlefield|isbn=978-1-882289-33-2}}</ref> This would correspond to the period necessary to bring a child to relative independence in the traditionally small, interdependent, communal societies of pre-Neolithic humans, before they settled into agricultural communities.<ref name="pmid12962309" />

While genetic evidence typically displays a bias towards a smaller number of men reproducing with more women, some regions or time periods have shown the opposite. In a 2019 investigation, Musharoff et al. applied modern techniques to the 1000 Genomes Project Phase 3 high-coverage Complete Genomics whole-genome dataset.<ref name="pmid31539367">{{cite journal | last1=Musharoff | first1=Shaila | last2=Shringarpure | first2=Suyash | last3=Bustamante | first3=Carlos D. | last4=Ramachandran | first4=Sohini | title=The inference of sex-biased human demography from whole-genome data | journal=PLOS Genetics | publisher=Public Library of Science (PLoS) | volume=15 | issue=9 | date=2019-09-20 | issn=1553-7404 | doi=10.1371/journal.pgen.1008293 | page=e1008293| pmid=31539367 | pmc=6774570 | doi-access=free }}</ref> They found that the Southern Han Chinese had a male bias (45% female, indicating that women were likely to reproduce with multiple men). This region is known for its lack of a concept of paternity and for a sense of female equality or superiority.<ref>{{cite news |last=Booth |first=Hannah |url=https://www.theguardian.com/lifeandstyle/2017/apr/01/the-kingdom-of-women-the-tibetan-tribe-where-a-man-is-never-the-boss |title=The kingdom of women: the society where a man is never the boss |work=The Guardian |date=2017-04-01 |accessdate=2023-06-28 |archive-date=22 June 2023 |archive-url=https://web.archive.org/web/20230622043118/https://www.theguardian.com/lifeandstyle/2017/apr/01/the-kingdom-of-women-the-tibetan-tribe-where-a-man-is-never-the-boss |url-status=live }}</ref> The Musharoff study also found a male bias in Europeans (20% female) during an out-of-Africa migration event that may have increased the number of men successfully reproducing with women, perhaps by replenishing the genetic pool in Europe. The study did confirm a more typical female bias in Yorubans (63% female), Europeans (84%), Punjabis (82%), and Peruvians (56%).<ref name="pmid20453016">{{cite journal| author=Keinan A, Reich D| title=Can a sex-biased human demography account for the reduced effective population size of chromosome X in non-Africans? | journal=Mol Biol Evol | year= 2010 | volume= 27 | issue= 10 | pages= 2312–21 | pmid=20453016 | doi=10.1093/molbev/msq117 | pmc=2944028 }}</ref>