Evolutionary psychologists commonly assert that some trait or propensity identified in lab studies is universal or pan-human and this means the trait or propensity evolved for adaptive reasons in the ancestral past. The problem with most such studies is that the test subjects are highly derived or WEIRD: “white, educated, industrialized, rich, democratic.” It is exceedingly odd to infer, based on studies of weirdos, that traits or propensities are human universals. This is especially true when it comes to sex preferences, which are notoriously malleable and strongly conditioned by culture.
A recent PNAS study examined allegedly universal or “ancestrally evolved” sex preferences using test subjects from a wide variety of cultures. The findings, unsurprisingly, are significantly at odds with those that dominate headlines here in the West:
It is a popular assumption that certain perceptions—for example, that highly feminine women are attractive, or that masculine men are aggressive—reflect evolutionary processes operating within ancestral human populations. However, observations of these perceptions have mostly come from modern, urban populations. This study presents data on cross-cultural perceptions of facial masculinity and femininity. In contrast to expectations, we find that in less developed environments, typical “Western” perceptions are attenuated or even reversed, suggesting that Western perceptions may be relatively novel.
A large [evolutionary psychology] literature proposes that preferences for exaggerated sex typicality in human faces (masculinity/femininity) reflect a long evolutionary history of sexual and social selection. This proposal implies that dimorphism was important to judgments of attractiveness and personality in ancestral environments. It is difficult to evaluate, however, because most available data come from large-scale, industrialized, urban populations. Here, we report the results for 12 populations with very diverse levels of economic development. Surprisingly, preferences for exaggerated sex-specific traits are only found in the novel, highly developed environments. Similarly, perceptions that masculine males look aggressive increase strongly with development and, specifically, urbanization. These data challenge the hypothesis that facial dimorphism was an important ancestral signal of heritable mate value.
These findings militate in favor of methodological caution. There is also a large evolutionary psychology literature which asserts that allegedly universal cognitive traits give rise to and sustain “religious” beliefs. Most of these studies are based on tests of weirdos. Until these findings are replicated and confirmed cross-culturally, we should be cautious.