Recent studies have revealed an interesting trend in the physical development of men and women over the past century, particularly in terms of height and weight. While the rise of tall, broad-shouldered men, seemingly confident and imposing, might not have caught everyone’s attention, it’s a shift that’s hard to ignore when examined through the lens of global health data. Men have been growing in size at twice the rate of women, which has contributed to a widening gap between the sexes in terms of physical stature.
A Guardian report on Wednesday quoted Prof. Lewis Halsey from the University of Roehampton, saying this phenomenon is tied to sexual selection and improved living conditions. Enhanced access to nutrition and a reduction in disease burdens have allowed both men and women to reach greater physical potential, though men have benefited more.
Halsey and his team used data from the World Health Organization, UK records, and other international sources to explore how height and weight have evolved in response to better living conditions, which they measured using the Human Development Index (HDI). This index takes into account life expectancy, education levels, and income, with values ranging from 0 to 1.
The study's findings showed a clear trend: for every 0.2-point increase in HDI, women grew, on average, 1.7 cm taller and gained 2.7 kg, while men grew 4 cm taller and gained 6.5 kg. This suggests that as living conditions improve, both men and women grow taller and heavier, but the changes in men are more pronounced.
Focusing on the UK, where HDI rose from 0.8 in 1900 to 0.94 in 2022, historical height records showed that men’s average height increased more significantly than women’s. For example, between 1900 and 1950, the average height of men grew by 4%, from 170 cm to 177 cm, while women’s height grew by only 1.9%, from 159 cm to 162 cm. The gap between the sexes in terms of height has become more noticeable over time; by 1958, only about one in eight women was taller than the average man, compared to one in four in 1905.
The study, published in Biology Letters, explores the possibility that women’s sexual preferences may have contributed to the trend of taller, more muscular men. Stature and physique are often seen as indicators of health, vitality, and the ability to protect and defend, qualities that might be especially appealing in a mate. Taller men, according to Halsey, might signal good genetic health and environmental resilience, indicating that they have reached their full growth potential and are well-equipped for survival.
While the trend toward taller men may be driven by evolutionary preferences, there are some drawbacks to being tall. Taller individuals tend to earn higher wages, but they are also more susceptible to certain health risks, such as cancer, due to the greater number of cells in their bodies, which increases the potential for mutations.
Michael Wilson, a professor of ecology and evolution at the University of Minnesota, noted that the rapid increase in male size is consistent with a long-standing theory that females are more ecologically constrained due to the energy demands of reproduction, particularly during pregnancy and nursing. As such, men are more sensitive to improved nutritional conditions, growing larger bodies when exposed to energy-dense food.
Overall, this research highlights how shifts in environment, nutrition, and reproductive strategies have influenced the physical evolution of men and women, with men’s growth being notably more pronounced in recent history.