Masculine Men and Feminine Women: Modernity May Cause Sexual Preference

When it comes to sexual preference, our culture idealizes feminine women and masculine men. Yet a new study may show that this may not have always been the case for humans. It turns out that instead of a long process of social and sexual selection, this preference may be a relatively new habit that has emerged in modern, urbanized societies.

In order to better understand the preference for feminine women and masculine men, the researchers surveyed 12 populations around the world, from the primitive to the highly developed. They showed a total of 962 participants sets of three opposite-sex composite and digitally manipulated photos. For each set of photographs, representing five different ethnic groups, participants were asked which face was most attractive and which appeared most aggressive.

"We digitally morphed masculine and feminine faces from photographs of people to find out what choices people from small-scale societies made," said Andrew Clark, one of the researchers, in a news release. "We found that they didn't place the same emphasis on 'sex typicality,' that is, on highly feminine women and highly masculine men. In fact, they often favored the neutral face, and sometimes the least 'sex-typical' one."

In fact, the researchers found that the perception that masculine males appear aggressive increased with urbanization. It's possible that highly developed environments with large, dense populations may have exposed individuals to a greater range of unfamiliar faces, providing the opportunity to discover subtle relationships between facial traits and behavior.

"This data challenges the theory that exaggerated sex-specific traits were important for social and sexual selection in ancestral environments," said Clark. "Preferences for sex typical faces are a novel phenomenon of modern environments. It's probably not a consistent thread in human history."

The findings reveal a bit more about how sexual preferences develop and what may cause them. This, in turn, reveals a bit more about how humans are influenced by their environment.

The findings are published in the journal Proceedings of the National Academy of Sciences.