For decades, it has been widely believed that certain features of female appearance — a narrow waist, a high voice, or soft facial traits — signal high fertility. Evolutionary theory explained this by suggesting that men instinctively choose women who “look” more reproductively successful. A new study challenges this long-standing idea.
A research group led by Linda Lidborg from Durham University analyzed data from more than 125,000 women across 16 countries. The scientists compared physical traits with real measures of fertility — number of children, pregnancy history, and offspring survival. The results were surprising.
The most studied parameter was waist-to-hip ratio, and it showed the opposite of what people expected: women with less defined waists often had more children. The authors suggest that body shape reflects the consequences of pregnancy rather than its potential. In other words, rounder figures may be the result of childbirth, not a predictor of it.
Other features also failed to show consistent patterns. Breast size studies produced contradictory results, voice pitch showed a correlation in one ethnographic group and none in another, and finger-length ratios proved to be so weakly associated that they were practically insignificant.
Interestingly, the researchers did not find a single analysis that convincingly linked feminine facial traits to real fertility, despite the popularity of this idea in evolutionary psychology.
The authors conclude that the current evidence does not support the idea that typical “feminine traits” are reliable biological indicators of reproductive potential. At the same time, many questions remain, and scientists continue to investigate the factors that shape human appearance.