Preferences for masculine men and feminine women may emerge only in highly developed environments, according to a new research.
Scientists from Brunel University London and the University of Bristol surveyed twelve populations of varying economic development located around the world.
Preferences for exaggerated sex specific traits were found only in highly developed environments, researchers said.
Nine hundred and sixty-two participants were shown sets of three opposite-sex composite photographs, that had been digitally manipulated to show varying levels of masculinity and femininity.
For each set of photographs, representing five different ethnic groups, participants were asked which face was most attractive, and which appeared most aggressive.
Preferences for sex specific traits were found only in highly developed environments. Perceptions that masculine males appear aggressive also increased with urbanisation.
These data challenge the theory that exaggerated sex specific traits were important for social and sexual selection in ancestral environments.
The authors speculated that highly developed environments with large, dense populations may expose individuals to more unfamiliar faces, perhaps providing the opportunity - and motive - to discern subtle relationships between facial traits and behaviour.
The study is published in the journal PNAS.
