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How Old Are You in Your Head? The Neuroscience of Subjective Age Reveals How to Stay Mentally Young

Jessica Stillman
4 min readApr 30, 2024


My 70-year-old father tells me he’s routinely startled simply by seeing his face in the mirror. “Who’s that old guy?” he thinks. Science shows he’s far from alone in this feeling.

Neuroscientists have explored the puzzling gap between our real age and how old we feel in our heads (aka our “subjective” age) and discovered that, on average, middle-aged adults in Western societies feel 20 percent younger than their actual number of years.

I’m 43, so this formula says I probably feel about 35, and my father is likely expecting to see a less wrinkly and white-haired 56-year-old in the mirror. Sounds about right.

But what does science have to say about why this common pattern exists and what, if anything, you can do to change your subjective age?

How old do you feel?

It may be clear that most adults feel younger than they are. Why remains a bit of a mystery. This long Atlantic article from Jennifer Senior offers several fascinating possibilities, as well as great anecdotes from a variety of people about their own inner age.

One theory is that years rich in new experiences seem to make more of an impression on our brains. When we enter into…