A groundbreaking study has revealed that men globally have experienced a faster increase in height and weight compared to women over the past century. Analysis of historical records from various countries demonstrated significant differences in the physical developments of men and women, correlating with improvements in living conditions as measured by the Human Development Index (HDI).
The HDI, which ranges from zero to one, is a composite score that evaluates life expectancy, educational attainment, and per capita income. An increase of 0.2 points in HDI was associated with women gaining an average of 1.7 cm in height and 2.7 kg in weight, while men gained 4 cm in height and 6.5 kg in weight. This rapid increase in male stature and physique highlights the role of both health and sexual selection in human evolutionary biology.
The research, conducted by Prof. Lewis Halsey and his team using data from the World Health Organization, overseas authorities, and UK records, underscores the importance of living conditions in determining physical development. In the UK, for example, the HDI rose from 0.8 in 1900 to 0.94 in 2022. During the first half of the century, the average height for women increased by 1.9% from 159 cm to 162 cm, while men's average height rose by 4% from 170 cm to 177 cm.
“We’re seeing insights into how sexual selection has shaped the male and female body and how improved environments, in terms of food and a lower burden of disease, have freed us from our shackles,” – Prof Lewis Halsey
Prof. Halsey further elaborated that sexual selection favors men who can protect and defend their partners and offspring, explaining why men might be evolving towards greater physical stature. This study suggests that larger male body size is not only a condition-dependent trait but also a sexually selected one.
“The sexy and formidable male body: men’s height and weight are condition-dependent, sexually selected traits” – Prof Lewis Halsey
Michael Wilson, a professor of ecology, evolution, and behavior at the University of Minnesota, described the faster increase in male height and weight over the century as "striking." Such growth trajectories suggest that males are more responsive to nutritional improvements than females.
“Investment in greater body size by males appears to be sensitive to nutritional conditions,” – Michael Wilson
The implications of these findings extend beyond mere statistics. Prof. Halsey noted how historical data reveals shifts in societal norms and expectations regarding male and female physicality.
“To put this in perspective, about one in four women born in 1905 was taller than the average man born in 1905, but this dropped to about one in eight women for those born in 1958,” – Prof Lewis Halsey
“Women can find men’s height attractive because, potentially, it makes them more formidable, but also because being taller suggests they are well-made,” – Prof Lewis Halsey
“As they’ve grown up, they haven’t been affected by the slings and arrows of a bad environment, so they’ve reached more of their height potential. It’s an indicator that they’re well-made,” – Prof Lewis Halsey