Guys, do you prefer more feminine faces? If so, chances are you grew up in a relatively healthy place. New research suggests that men raised in countries with higher average lifespans and lower child mortality more strongly prefer women with softer features than do men raised in less healthy nations. The finding bolsters the idea that years of human evolution have made men attracted to faces that could help them survive.

Previous studies have found that women living in harsher conditions—such as communities with high homicide rates and low income—are more inclined to find more masculine men attractive. Urszula Marcinkowska, a biologist at the University of Turku in Finland, and her colleagues wanted to know whether culture also influenced males’ preferences for females, or whether men judged females in a more universal way.

Using an online survey conducted in 16 different languages, the researchers presented 1972 heterosexual males between the ages of 18 and 24 from 28 different countries with 20 pairs of Caucasian female faces. Each pair contained one face with more feminine traits—such as larger eyes, fuller lips, and a less angular jaw—as well as a more androgynous face, with thinner lips and a wider chin. Participants were asked to select which face in each pair they found more sexually attractive.

While men across all cultures generally preferred a more feminine face, the strength of that preference varied between countries. The difference couldn’t be explained by the ratio of men to women in a country, its gross national income, or the race of the participants, but it did correlate with the national health index of the men’s countries—a measure of overall well-being. Those from countries like Japan, with high national health index scores, chose the more feminine face more than three-quarters of the time, the authors report online today in Biology Letters. Men from countries such as Nepal, which has a lower health rating, selected the more feminine face in only slightly more than half of the cases, on average.

“Women with more feminine features have, in the past, been found to be less socially dominant and less effective at competing for resources,” Marcinkowska says. Over thousands of years, she says, men may have evolved to choose less feminine women in harsher conditions to give them an edge at survival. One possible mechanism mediating this preference is altered testosterone levels; men raised in environments with frequent diseases and germ exposure tend to have lower testosterone levels through adulthood, because testosterone can handicap immune function. And men with high testosterone levels, previous studies have found, prefer more feminine women.

“Unfortunately we couldn’t measure participants’ testosterone levels in this study,” Marcinkowska says. “However, I think this explanation is very plausible.”

The conclusions “seem reasonable,” says Anthony Little, a psychology researcher at the University of Stirling in the United Kingdom who was not involved in the new work. But he also points out that separate studies have shown that recent pathogen exposure can increase a male’s preference for femininity, a slightly contradictory finding. “Future work can perhaps tease out whether different mechanisms are at play in driving these different effects.”

Marcinkowska next plans to look at additional characteristics of the countries included in the survey to see whether other differences may also be linked to the face preferences. She hopes the results add to the collection of data on how people use faces to judge others, and how these preferences may have evolved.