A majority of the men out there spend hours in the gym for one reason: to attract women. The reason for their endless iron pumping is the age-old stereotype that women are more attracted to manly men compared to feminine-looking men. A recent study conducted at Brunel University London has revealed that the opposite sex’s attraction to masculine men and feminine women is a modern occurrence in highly developed cultures and what men and women really desire is facial neutrality.

"We digitally morphed masculine and feminine faces from photographs of people to find out what choices people from small-scale societies made,” Dr. Andrew Clark lecturer in psychology at Brunel University London, said in a statement. "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 favoured the neutral face, and sometimes the least 'sex-typical' one."

Clark and his colleagues recruited 962 people representing 12 different ethnic backgrounds, from underdeveloped to highly developed. Participants were shown three sets of photos that were digitally manipulated to either make men look more feminine or women look more masculine. Models in the photos were from five different ethnic groups. After viewing each photo, participants were asked: “What face is the most attractive?” and “What face is the most aggressive looking?”

Only participants from highly industrialized and urban areas fit the stereotype of being attracted to highly masculine men or highly feminine women. On the other hand, female participants from less industrialized environments, such as South America, were more attracted to men with a feminine look. The research team speculated that dense populations found in highly developed areas give us the opportunity to notice the relationship between facial traits and behaviors exhibited by unfamiliar faces. Findings also showed that people in urban areas associated masculinity with aggression.

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

Unfortunately for manly men, the adverse effects of being overly masculine doesn’t stop at attraction. Research conducted on 62 college students from Columbia and Spain recently found that masculine men suffer from poor sperm motility due to higher testosterone levels. “This suggests that male facial cues may provide culture- and sex-independent information about male fertility,” the researchers wrote.

Source: Josephson S, Scott I, Clark A, et al. Human preferences for sexually dimorphic faces may be evolutionarily novel. Proceedings of the National Academy of Sciences. 2014.