Being a ‘sexy and formidable’ bloke wasn’t always an advantage in life.
Every man wants to be a macho, macho man
To have the kind of body always in demand
Joggin’ in the mornings, go man go
Workouts in the health spa, muscles grow
We have President Donald Trump to thank for the late-career revival of 1970s novelty disco act Village People, courtesy of the Donald’s “dad dancing” to their hit tune, YMCA, at his election rallies.
But it is the group’s earlier hit, Macho Man, that seems to have tapped into an evolutionary phenomenon that scientists believe goes some way towards explaining why human males, by and large, are taller and weigh more than females.
Now before you hit the cancel button, let us be at pains to point out we are talking in generalisations here based on a broad sweep of data, and we fully accept that there are multiple variations of sexuality and gender that can and do exist among humankind.
But as a paper published this week in the journal Biology Letters says, the “size dimorphism” between males and females has more than doubled over time, mainly due to improved living conditions making it safer for men to be “big and muscly” and for those traits to be passed on more successfully thanks to female sexual selection.
To reach these conclusions, an international team of researchers looked at WHO data on changes in height and weight in around 135,000 people from 62 countries as disease burden decreased, as well as adult height data from Wikipedia and a previous UK study.
What they found was, while being “sexy and formidable” (their words, not ours) conferred advantages in the mating game, that size came with the hidden cost of being more vulnerable to disease. But as living conditions improved, being a tall and ripped male became a safer bet than it once was.
What’s more, as disease burdens decrease, the differences in height and weight between men and women widens.
“Men are on average taller and more muscular than women, traits that confer advantages in female choice and male competition. These size dimorphisms come with higher developmental costs, aligning with evolutionary theory that larger, sexually selected traits signal health and vitality but are more vulnerable to stressors like disease,” the study authors said in a media release.
“Our large-scale analysis shows that with cross-national improvements in living conditions, men’s height and weight increase more than double that of women, amplifying size dimorphism.”
The authors added that their study offered “insights into how socio-ecological factors and sexual selection shape key physical traits”.
Or as we would put it more prosaically, it suggests Charles Atlas was right: the beefcakes do get the girls and the 90-pound weaklings get sand kicked in their faces.
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