“In “How Men Age” biological anthropologist Richard Bribiescas covers some interesting uncharted territory. This is not a mere description of getting older. Instead, by considering male ageing in the light of natural selection, it aims to answer why men’s lifespans are shorter than women’s, why baldness, prostate disease and erectile dysfunction are so prevalent, and how humans as a species have benefited from men’s tendency to get fat.
“From an evolutionary perspective, nothing matters more than sex. And as far as men are concerned, nothing influences sexual power more than testosterone. It increases libido, promotes muscle growth and encourages risk-taking behaviour – all of which help attract a mate. But testosterone peaks in early adulthood, so that men are past their physical prime by the age of 30. It’s tempting to see it as all downhill from there. But Bribiescas shows convincingly that’s not the case. He points out that testosterone has a dark side – it can increase a man’s metabolic rate and suppress the immune system. In other words, there’s a trade-off. High levels of the hormone early in life help explain why men don’t live as long as women and why they are prone to prostate cancer later on. So waning testosterone can be seen as a positive development. It may make older men less physically competitive against younger ones, but men can produce offspring throughout their lives and, argues Bribiescas, as they age they develop new reproductive strategies to achieve this.
For a start, although they may lack raw strength, their experience often makes them better providers than their younger counterparts. Bribiescas has done fieldwork with the Ache people of Paraguay, and points to research showing that men’s hunting success peaks in their 40s, long after their testosterone levels peak. What’s more, older men tend to become more nurturing. As testosterone decreases, a man’s girth increases, and the metabolic changes associated with growing adiposity* promote care of offspring. Bribiescas calls this the “pudgy dad hypothesis”, and argues that it has implications for the evolution of our species as a whole.
Humans live far longer than other primates. For longevity to evolve, natural selection must favour long-lived individuals. Older women cannot reproduce, so they are out of the running. But if, throughout human history, older men have been fathering children, then they will have passed on genes associated with longevity to both daughters and sons. Old men, therefore, could be the reason we all live so long. It would appear there is some point to them after all. (review by Kate Douglas, New Scientist, of “How Men Age: What evolution reveals about male health and mortality”, by Richard Bribiescas, Princeton University Press.
(* denoting body tissue used for the storage of fat)
I have also been wondering what the point of old men is. I concluded that the only reason for them is to bring the credit card with them to the restaurant to pay for the meal, and then to leave the tip. However, after serious thought I think they have other functions: to tell stories, make people laugh and to tell the truth about life. And, Oh, the freedom you feel when you can’t be fired and you no longer care so much about what people think of you! Epicurus clearly had old men in mind when he developed his philosophy, there in his garden.
