Owing to long-held habits like drinking, smoking, and warring, men have traditionally come up short when it comes to life expectancy. In 2016, the National Center for Health Statistics released data indicating women in the U.S. could expect to live an average of 81.1 years. Men, 76.1. That's a full five fewer years of enjoying this mortal coil. To pose a scientific question—what gives?

In an essay penned for Nautilus, Richard G. Bribiescas, a professor of anthropology, ecology and evolutionary biology at Yale University, believes that the answer rests outside of the male gender making poor life choices. Biologically, men may look forward to curtailed lifespans because of the hormone testosterone.

Bribiescas argues that, while testosterone provides beneficial boosts in libido, mood, and aggression—all key, in some measure, to both survival and reproduction—there is a biological price paid for the markedly higher levels seen in men than women. Testosterone can affect the body's immunological response, suppressing the immune system and making men more susceptible to illness. The hormone has also been associated with increased cancer risk, including prostate cancer.

Evolution seems to have put up with testosterone because of its impact on reproduction, which is why the male body hasn't come up with a way to dismiss the hormone. But men might not be losing years for much longer. A statistical analysis by Cass Business School in the UK forecasts men and women may both live an average of 87.5 years by 2032. Longevity may improve as a result of less alcohol consumption and smoking, as well as better treatments for heart disease. But that's simply a prediction. It may be that testosterone will continue to be an inherent risk factor for males, one that no lifestyle changes can outpace.

[h/t Nautilus]