Women's waists and the sex ratio of their progeny: evolutionary aspects of the ideal female body shape

It is shown that in a sample of 102 women, aged from 35–55 years, components of female size i.e., weight, waist circumference, hip circumference and waist:hip ratio are positively correlated to the proportion of sons in their family.

Abstract

There is some evidence that testosterone levels in women are correlated with a tendency to produce sons. We show that in a sample of 102 women, aged from 35–55 years, components of female size i.e., weight, waist circumference, hip circumference and waist:hip ratio are positively correlated to the proportion of sons in their family. Multiple regression analysis shows that of these variables it is waist circumference which is the strongest predictor of the proportion of sons. It is argued that in many traditional societies, where rank is inherited by males and females often marry upwards, high ranking males should prefer heavy women with thick waists and hips. By this means they increase their probability of having sons to inherit their rank. In less stratified societies other negative correlates of female size such as symmetry, health and fertility will result in a preference for light women with small waists and hips.