The "brain isn't done until 25" factoid is based on a funding cutoff

[](https://boingboing.net/2026/02/19/new-research-debunks-the-brain-at-25-factoid.html "The "brain isn't done until 25" factoid is based on a funding cutoff")

You've seen the claim on TikTok, in parenting forums, and in roughly a million Instagram infographics: "Your brain isn't fully developed until you're 25." It's the go-to explanation for everything from bad relationships to impulsive tattoos. The number 25, though, has almost nothing to do with neuroscience. — Read the rest

The post The "brain isn't done until 25" factoid is based on a funding cutoff appeared first on Boing Boing.