The common belief that certain physical traits of women are biological indicators of high fertility is not supported by scientific evidence. This conclusion is presented in a new review of studies published in the journal Evolutionary Human Scienceswrites Рsypost.

Evolutionary biology traditionally attributes differences between men and women to mechanisms of sexual selection: men are assumed to prefer “feminine” traits—a low waist-to-hip ratio, a high-pitched voice, or “feminine” facial features—because they are supposedly associated with reproductive success. By this logic, women with pronounced such characteristics should give birth to children.

However, the lead author of the review, research fellow at Durham University (UK) Linda Lidborg, notes that existing data do not confirm this.

Stereotype refuted

The researchers analyzed 19 studies, including data from than 125,000 participants from 16 countries, where physical parameters were compared with objective indicators of fertility: number of children, pregnancy history and offspring survival.

The most popular characteristic was waist and hip measurements. Contrary to established hypothesis, women with higher ratios—that is, smaller waistlines—often had children. The authors suggest that body shape often reflects the consequences of pregnancy rather than its potential.

Other parameters also did not show consistent patterns. Two studies of breast size found opposite results, and a third found no connection at all.

Analysis of voice pitch showed a positive correlation in one ethnographic group and no correlation in another.

Studies on finger length ratio, sometimes used as a proxy for hormonal levels, have also produced conflicting data with very weak effects.

Interestingly, the researchers found no analyzes linking facial femininity to actual fertility, despite the idea’s popularity in evolutionary psychology.

Questions remain

The authors emphasize that the current evidence base does not allow us to assert that typical “signs of femininity” serve as reliable biological indicators of reproductive potential.

However, the review also notes a number of limitations of the work: most studies were conducted in developed countries where contraception is common, making it difficult to assess natural fertility.

“There are many reasons why differences between men and women are formed—attractiveness is just one of them. Some traits are related to the physiology of birth, others have no clear adaptive function. We continue to study the factors that shaped human appearance,” notes Lidborg.