New Study Shines a Light on Why Women Live Longer Than Men

The science of longevity and what causes people to live longer is fascinating. And one fact that has been widely known is that women tend to live longer than men. But what’s behind this?

A new study in Science Advances analyzed lifespan differences across hundreds of mammal and bird species. The findings suggest that while genetics and evolutionary factors play a role, behavior may also have a significant influence.

The Longevity Gap
In the US, in 2021, the longevity gap between men and women stood at 5.8 years, NPR reports. On average, men live about 76 years, while women live 81 years. What is interesting, however, is that this is true not only among humans, but also among mammals, according to the study. Females live about 13 percent longer in 72 percent of the 528 mammal species studied.

Biology may be behind this, according to People. Mating practices and caretaking responsibilities may explain the longevity gap among mammals, which might help understand the life expectancy gap in humans. In addition, females may have a genetic advantage because they have two X chromosomes, which can protect against genetic mutations.

Interestingly, this pattern of longer lifespans is only seen in mammals, and not in birds, amphibians, and insects. As Dr. Fernando Colchero, one of the leads on the study, tells NPR: “What we found is that this female advantage in longevity is part of the evolution of mammals. It goes back millions of years.”

It Comes Down to Behavior
As it turns out, the reason behind the longevity gap between females and males is that it is not only genetic but also behavioral. In animals, males tend to engage in risky behavior in order to attract a mate. For instance, male deer grow antlers and fight rivals to compete for mates. This can be advantageous, evolutionarily speaking, as it means their genes will survive while their rival’s genes will not, however, it also comes with the risk of death.

Though human men, at least ostensibly, do not fight other men to attract a mate, they are still more likely to engage in risky behavior than women. Interestingly enough, though men have a slightly higher incidence of getting melanoma, they are more likely to die of the disease than women are. This is partly because men tend to go to doctors less often to check for cancer.

This illustrates that the old ‘nature versus nurture’ debate is misleading. It is nature and nurture. It is not only genes nor only behavior that leads to a longevity gap between females and males in mammals, but rather both.

Luckily, that means that there are ways to close that gap. Men can make an effort to engage less in risky behaviors and see their doctors more often. A 5.8-year deficit in average lifespan is not a genetic absolute but a combination of the results of behaviors and genetics, and behaviors can always be changed through choices.