Almost ten million more American women have been vaccinated against COVID-19 than men. This is partially explained by the fact that women tend to live longer and elderly Americans were given the first priority for shots. Women also make up a higher percentage of health care workers, a group which was given early access to inoculations. But, the gender disparity really shouldn’t be a surprise. In general, men are less likely to seek health care. They’re also less likely to worry about the safety of others, and they’re less deferential to experts.

Researchers are nearly unanimous in their assertion that traditional masculinity — the idea that men should be self-reliant, physically tough and emotionally stoic — is a risk factor for men’s health. James Mahalik, an expert on masculinity and health outcomes at Boston College, studies how traditional masculinity gets in the way of health-promoting behaviors. His lab’s research on mask-wearing indicates that men who conform to traditional masculine norms have lower levels of empathy toward people who are vulnerable to COVID-19, and they are less likely to trust the scientific community. Mahalik suspects the same is true for their views about the vaccine.

Of course, this distinction also exists between liberals and conservatives. And it’s showing up in the statistics.

Covid-19 transmission is accelerating in several poorly vaccinated states, primarily in the South plus Missouri and Utah, and more young people are turning up at hospitals. The data present the clearest sign of a rebound in the U.S. in months.

In Missouri, Arkansas and Utah, the seven-day average of hospital admissions with confirmed Covid-19 has increased more than 30% in the past two weeks, according to the U.S. Department of Health & Human Services. In Mississippi, the hospitalization rate is up 5% in the period.

A map of the least vaccinated counties in the country looks roughly like the red states on an Electoral College map of the 2020 presidential election. These are areas where “traditional masculinity” is highly prized. It turns out, however, that an emphasis on being “a real man” is pretty good at shortening your life.

According to Dr. Jonathan Metzl, director of the Center for Medicine, Health, and Society at Vanderbilt University, men’s shorter lifespans are the result of the cumulative effects of poor health decisions, not physiology. “There’s no real biological reason that men die earlier,” said Metzl. “The things that make you a successful, cool, tough man in America are also inversely related to health and longevity.”

The more we follow traditional masculine ideas about health care instead of listening to experts, the more of us will die. This can be seen now in the way the highly transmissible and more dangerous Delta variant of the COVID-19 virus is spreading rapidly in the least vaccinated counties of the country but not much at all in the counties that voted for Biden.

In short, we shouldn’t let people who don’t go to the doctor or listen to doctors’ advice guide our health care policy or decisions.