BY THE OPTIMIST DAILY EDITORIAL TEAM

Across the animal kingdom, females tend to live longer than males, and the same is true for humans. In the U.S., the gap has actually increased to 5.8 years in 2021. The average life expectancy for men is nearly 76 years, while women live to around 81 years. According to researchers at the Max Planck Institute for Evolutionary Anthropology, this gap isn’t a modern phenomenon. It’s part of a much older story.

“What we found is that this female advantage in longevity is part of the evolution of mammals. It goes back millions of years,” explains study author Fernando Colchero. Their research, published in Science Advances, analyzed 528 mammal species and found that in 72 percent of them, females outlived males by about 13 percent on average.

So what’s behind this biological trend? The answer lies in a mix of genetics, behavior, and even parenting roles.

Biology plays a part

From a genetic standpoint, females have an edge. With two X chromosomes, they carry a kind of backup system to protect against harmful mutations. Males, with one X and one Y chromosome, don’t have the same built-in safeguard.

But it’s not just about chromosomes. The evolutionary pressures on male mammals often include competition for mates. In species like deer, for instance, males grow antlers and increase in size to intimidate rivals. This kind of physical transformation drains energy and shortens lifespan.

“This is an evolutionary pressure, certainly, to be able to pass to the next generation as many genes as they can,” Colchero says. “But that comes at a cost in their survival.”

Risky behaviors take a toll

Human males might not grow antlers, but they do tend to engage in riskier behaviors. “Men are also more likely than women to die of alcoholism, drug use, suicide and homicide,” says Alan Geller, a senior lecturer at Harvard T.H. Chan School of Public Health.

Smoking, for example, has historically been more common among men, contributing to higher rates of lung cancer and heart disease. And while smoking rates have declined, the long-term impact still lingers in life expectancy data.

Geller also points out that men die at higher rates from melanoma, even though women are more likely to be diagnosed with it. Why? One factor is skin biology: men’s skin is thicker and contains more collagen, which may make it more susceptible to sun damage. But behavior matters too. Only 12.3 percent of men wear sunscreen regularly, according to a 2022 CDC report.

Add to that the fact that men are less likely to seek preventive care or regular screenings, and the gap in outcomes widens. “They are less likely to go to the doctor to ask for a skin cancer examination or examine their own skin,” Geller says. “And so you have a double whammy.”

Caregiving may extend life

The Max Planck researchers also observed that the caregiving sex tends to live longer. In mammals, the parent that invests more time in raising offspring often has higher survival rates. Evolution may favor a longer life for those responsible for a child’s early development.

While caregiving roles vary widely in humans, many men today are increasingly involved in parenting, which could offer long-term health benefits. Colchero believes these behavioral shifts could help narrow the longevity gap.

“There are ways in which we can reduce it to some extent,” he says. From wearing sunscreen to scheduling regular checkups, mimicking some of the health-preserving habits more commonly seen in women may go a long way.

Living longer, together

According to the American Heart Association, the top risk factors for most chronic diseases are modifiable. Their Life’s Essential 8 includes: eating better, being more active, quitting tobacco, getting healthy sleep, managing weight, and keeping blood pressure, cholesterol, and blood sugar in check.

Preventive care and healthier choices aren’t just good advice for women; they’re powerful tools for men too. As Geller puts it, much more could be done to promote screenings and lifestyle shifts among men. And as gender roles evolve, so too can our health habits.

“Let’s make sure that we go to the doctor,” says Colchero. It might just help close a very old gap.

Source study: Science Advances—Sexual selection drives sex difference in adult life expectancy across mammals and birds