Short of sharing a full genetic sequencing, Barzilai says that family history is a pretty good predictive factor. That bodes well for Trump, Warren, and Biden, whose parents all lived well into their 80s. But then what to make of Sanders, who has already outlived both of his parents by several decades (and is expected to make a full recovery from his heart attack)? Barzilai acknowledges it’s not just about genes; social and environmental circumstances also help determine how long and how well a person lives.

Indeed, I found out that more powerful predictors of both longevity and cognitive stability even than genetics are three external factors: education, race, and wealth. Countless studies have found a correlation between income level and lifespan; a 2016 study published in the Journal of the American Medical Association, for example, found that on average, the richest 1 percent of American men live 14.6 years longer than the poorest 1 percent; for women the difference is 10.1 years. That’s not surprising: Being wealthy means you have access to good health care and good control over your diet and exercise.

Relatedly, level of education matters, too—and even more so along racial lines. In 2012, University of Illinois at Chicago gerontologist and public health researcher Stuart Jay Olshansky sorted deaths in the United States by age, race, and number of years of schooling. He found that on average, black men who hadn’t finished high school lived 14.2 years less than white men who had completed 16 or more years of education; for women that figure was 10.3 years. (It’s important to note that these racial differences probably have to do with lack of opportunity for African Americans, not any biological difference.)

Education also seems to have a strong protective effect against dementia: A 2018 University of Southern California study found that most people who have graduated from college can expect to prevent cognitive decline into their 80s, while people with a high school education often begin to experience it in their 70s. It’s not that education actually prevents the changes in the brain associated with dementia, explained Joe Verghese, another Albert Einstein gerontologist. Rather, education seems to help people compensate for those changes. “The theory is that people who are highly educated and intellectually engaged will be able to stave off the effects of this disease,” he said.

When you consider these external factors, good genes don’t seem as important. All of the presidential candidates are wealthy; all are exceptionally well educated. Take Sanders: It’s valid to speculate that perhaps one reason he has lived so much longer than his parents is that he has a college degree and robust finances, while his parents were poor immigrants who worked all their lives.

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In this country, the same set of extreme social privileges that propel someone to the position of frontrunner presidential candidate also protect against the typical ravages of old age. And that single fact, for better or worse, is a stronger predictor of candidates’ health than any senior-moment gaffe they might have over the coming months. “It’s entirely possible,” Olshansky told me, “that some of these folks running for president are super-agers.” We should all be so lucky.