This Is When We Actually Become Adults, According to Science

For a long time, it was believed that the prefrontal cortex—the part of our brain responsible for decision-making and impulse control—didn’t fully develop until the age of 25, which is when we’d become proper adults, basically. But this isn’t actually true; it was an oft-repeated myth that probably stemmed from an old study in which scientists looked at brain scans up until the age of 25. But no matter. We heard “25” and we ran with it. Probably because it sounded good. We were all dumb at 23, right?

That said, if you’re interested in when the brain truly does reach a certain level of maturity, a new study (not just an overzealous TikToker) may have quite a solid answer. According to researchers at the University of Cambridge , who scanned the brains of around 4,000 people between