American history in 2021, at age 78, questions swirled about whether there should be an upper age limit for the executive office. Now that we’re doing a different kind of math—Biden would be 86 at the end of a second term, and his presumptive rival, Donald Trump, would be 82—the question has become starker: Can someone in their 80s really have the mental dexterity and cognitive fortitude that the office requires?

Physiologically, we can’t stop our brains from changing. They start shrinking about 3 percent per decade after age 40, and that accelerates to about 5 percent per decade in our 80s. Our information-processing speed slows down, and it’s harder to quickly retrieve info or tune out background noise. Those functions likely get gummed up due to the hardening of blood vessels and the buildup of plaque in the brain.

Yet scientists are challenging previous conceptions of what these changes actually mean in our day-to-day lives. We know that brain volume decreases, says Scott A. Kaiser, M.D., director of geriatric cognitive health at the Pacific Neuroscience Institute in Santa Monica, California, “but that might not be all that important in terms of how the brain performs overall.” In fact, in some ways, an older brain is better equipped to manage the demands of a job that requires insight, emotional control, and good decision-making skills.

This is fueling a new cultural conversation around the idea that there are even benefits to having a brain that has been around for a while. It’s a discussion that’s well overdue, whether or not it’s an election year.