An international team of researchers analyzed data on the heights and weights of more than 135,600 non-obese men and women from around the world and linked that data with national levels of prosperity. While both men and women grow taller and heavier as countries become wealthier, the researchers found that the trend in men is twice that in women. In a January 22 study published in Biology Letters, the team suggests this is at least partially because of modern sexual preferences.
“Our cross-national analyses suggest that as the social and ecological conditions of nations improve, including reductions in overall disease burden, people’s height and weight increase, but more than twice as much in men as in women resulting in greater SSD [sexual size dimorphism],” the researchers from Italy, the U.S., and the U.K. wrote in the study. Sexual dimorphisms are physical differences between sexes of the same species.
The researchers speculate that women are more likely to choose taller and more muscular men as partners, while men, on the other hand, may care less about the height of women.
The dramatic difference in the increased height between sexes in more prosperous countries also suggests that men’s morphology might be more sensitive to the environment than that of women.
“Based on our main finding of SSD being greater in more favourable environments, it is clear that the development and maintenance of gross morphology is more sensitive to living conditions in men than in women, at least in terms of height and weight,” the researchers wrote in the study.
In other words, “as (the) ecological or economical situation improves and there is better access to resources, males gain more biological benefits than females. It is exactly opposite when the resources are scarce (males ‘suffer’ more than females),” biologist Bogusław Pawłowski of the University of Wrocław in Poland, who was not involved in the study, told CNN.
Though the researchers admit that their results can only show a correlation between the data (as opposed to any definitive cause-and-effect) they ultimately suggest that men’s height, as well as sex-based differences in height, could be useful biomarkers for monitoring changes to the health of populations.