Not Against Human Sexual Selection

Piotr Stojanow

July 2, 2019

The Lovers II by Rene Magritte

Tanner Greer posted recently Against Human Sexual Selection on his insightful blog. In it he takes issue with evolutionary psychology for explaing “female mate preferences and male phenotypes (…) through the frame of sexual selection”.


LATER PASTE THIS QUOTE SOMEWHERE. HE MAKES THE SAME MISTAKE. “human history” is merely an eyeblink on evolutionary scales, and the article has nothing to say about mate choice in prehistory.

the model they posit for female mate selection does not reflect how human mate selection actually worked for most of human history.

Greer first problem with the accounts of human sexual selection is “mate choice”. Or rather the lack of it:

Humans are not frictionless, autonomous mate calculators on two legs. They live embedded in a social organization that has immense control over everything they do—including who they mate. (…) For most of human history, marriage was an arrangement between families, not individuals. Married children were generally expected to live with one of the families from which they sprung. Parents and grandparents had a veto of matches they did not like, and usually had the authority force a match the principals did not like, especially if the principal in question was a woman.

He is right saying that humans don’t exist a vacuum. We are a social animal. Yet, we also didn’t evolve in a vacuum. Homo sapiens didn’t suddenly appear and started arranging marriages. We are but a blink on the human timeline. And we carry in us a heavy evolutionary baggage.

Moreover, as we learn from Evolutionary History of Hunter-Gatherer Marriage Practices:

Arranged marriages are inferred to go back at least to first modern human migrations out of Africa.

That’s just 70,000-60,000 years ago1. If that wasn’t enough, the jury is still out on whether earlier marriages were arranged:

Reconstructions are equivocal on whether or not earlier human marriages were arranged because several African hunter-gatherers have courtship marriages. (…) Put simply we do not yet know whether or not mitochondrial Eve’s marriage was arranged. (…) arranged marriages probably have an evolutionary history going back at least 50,000 years2.

To be fair the Scholar’s Stage quotes Buckner who relies on Sexual Selection Under Parental Choice. It has “data from 190 hunting and gathering societies”. It concludes that:

Because daughters’ preferences can be expected not to fully coincide with those of their parents, research to date may thus have simultaneously overestimated the contribution of female preferences to processes of sexual selection and underestimated the contribution of parental preferences to such processes.

I don’t dispute this claim. In fact, the research in Evolutionary History of Hunter-Gatherer Marriage Practices supports it:

Our reconstruction of the evolutionary history of hunter-gatherer marriage practices indicates that parents and other close kin likely had a significant influence on mate choice. (…) At present, it is probably safe to conclude that an important selective pressure on the evolution of human mate choice, certainly more than any other species, has been the direct, deliberate, and conscious intervention of parents and other close kin on the sexual lives of their descendants.

That said, it doesn’t negate female mate preferences.

Even assuming that women didn’t choose their mates doesn’t mean that there is no selection pressures on male traits. At the very least the arrange marriages would lead to women preferring high-status males, which seems to be the case:

Several standard sex differences replicated across cultures, including women’s greater valuation of social status and men’s greater valuation of physical attractiveness

Evidence of selection for men’s status was also confirmed by other studies3 4.

Women are also attracted to testosterone dependent traits even though

Men with low testosterone (feminine men) invest in relationships and offspring more than men with high testosterone (masculine men).

Moreover, do women not choosing mates mean that sexual selection is possible only in marriages? Surely adultery exist at least as long as marriages do. Or as Laura Betzig puts is “throughout history men married monogamously, but mated polygynously if they could afford it5.”

We find confirmation for this in the Optimal Number of Fathers: Evolution, Demography, and History in the Shaping of Female Mate Preferences:

Across cultures, formal polyandrous marriages are indeed exceedingly rare (few-er than 2% of human cultures are so classified). But informally, polyandrous arrangements are far more common due to extramarital affairs, to a shortage of women or inability of one man to provide security, to a husband’s “sharing” his wife with kin, age-mates or allies (which by some estimates is found in one-third of all human cultures), or due to women’s taking up with sequential matesover a lifetime. Because so little attention has been focused on these topics, however, it can be difficult to learn from the ethnographic record whether a woman was seduced, raped, complicitous, or the initiator, or whether the husband was dupedor supportive. For husbands are not always prohibitively jealous of their wives6

We have to keep in mind that marriages are not set in stone. As well as the fact that women could have children with more than one man:

Take the Aché of eastern Paraguay. At any one time, the majority of marriages are monogamous. Yet each of these unions at some point is likely to be polygynous or polyandrous. For marriage among foragers is inherently unstable, especially when unions are passing through a polygynous or polyandrous phase. The marriage dissolves from internal tensions due to male jealousy or to intolerance between co-wives. Sixty percent (11 of 18) of Aché men spent some (typically brief) amount of time in polyandrous marriages. Over their lives, most Aché women have children with two or more men7

It’s important that we don’t succumb to presentism and give moral judgements on the past when we lack the full picture. Animals evolve mating systems that minimize inbreeding hazards. From Ancient genomes show social and reproductive behavior of early Upper Paleolithic foragers we know that at least 34,000 years ago humans formed sophisticated social and mating networks to avoid inbreeding8. Arranged marriages were most likely used to cultivate the network. This gave homo sapiens an advantage over Altai Neanderthal groups who didn’t develop such a network and inbred instead9.

He even go as far as stating:

This is a problem for sexual-selection theories of male behavior. If the girls were not choosing their matches, what selection pressures on male traits could there be? Perhaps instead of speaking of the psychology of sexual selection, we should be speaking of the psychology of parental selection instead.

The same paper also agrees that:

How regulated marriage affected sexual selection on human mate choice preferences depends on several factors. One factor is the extent to which parental (and other senior kin) choices overlapped or diverged with that of offspring mate choice. Another factor is the extent to which marital partners chosen by parents were the actual genitors of the descendants. Worldwide extra-pair paternity rates have been estimated at around 9% [26], although there is much variation between as well as within populations [27]. Regarding the first issue, parent-offspring conflict over mate choice in contemporary Western populations has been found to contain considerable conflict of interest, as well as some expected overlap, in preferred attributes [28]–[31]. However, environmental novelty may render these findings unrepresentative of ancestral situations and a systematic examination of parental and offspring mate choice preferences among hunter-gatherers and other small-scale societies is warranted.

  1. A dispersal of Homo sapiens from southern to eastern Africa immediately preceded the out-of-Africa migration by Teresa Rito, Daniel Vieira, Marina Silva, Eduardo Conde-Sousa, Luísa Pereira, Paul Mellars, Martin B. Richards & Pedro Soares, Scientific Reportsvolume 9, Article number: 4728 (2019) 

  2. Walker RS, Hill KR, Flinn MV, Ellsworth RM. Evolutionary history of hunter-gatherer marriage practices. PLoS One. 2011;6(4):e19066. Published 2011 Apr 27. doi:10.1371/journal.pone.0019066 

  3. Apicella, C.L. (2014). Upper-body strength predicts hunting reputation and reproductive success in Hadza hunter–gatherers. Evolution and Human Behavior, 35, 508-518 

  4. Jonason, P. K., Li, N. P., & Madson, L. (2012). It is not all about the Benjamins: Understanding preferences for mates with resources. Personality and Individual Differences, 52, 306-310 

  5. Laura 

  6. Sarah Blaffer Hrdy, The Optimal Number of Fathers: Evolution, Demography, and History in the Shaping of Female Mate Preferences, Volume 907, Issue 1, Evolutionary Perspectives On Human Reproductive Behavior, April 2000, pp. 75-96, p. 82 

  7. Ibid., p. 85 

  8. Ancient genomes show social and reproductive behavior of early Upper Paleolithic foragers, Sikora M, Seguin-Orlando A, Sousa VC, Albrechtsen A, Korneliussen T, Ko A, Rasmussen S, Dupanloup I, Nigst PR, Bosch MD, Renaud G, Allentoft ME, Margaryan A, Vasilyev SV, Veselovskaya EV, Borutskaya SB, Deviese T, Comeskey D, Higham T, Manica A, Foley R, Meltzer DJ, Nielsen R, Excoffier L, Mirazon Lahr M, Orlando L, Willerslev E, Science 03 Nov 2017 : 659-662 

  9. Ibid. 

Get instant updates and email only goodies.