Everyone knows your brain hasn’t finished maturing until you’re 25. That’s so well-known, in fact, that some countries (like Scotland) have built it into their criminal justice system, giving lower sentences to under-25s—even very violent ones—on account of their immature brains.

But in this episode of The Studies Show, Tom and Stuart discuss what the evidence really says about when the brain matures—and the trickiness of linking important policy decisions to the science.

The Studies Show is brought to you by Works in Progress magazine, who don’t just have their magazine (at worksinprogress.co), but also have a Substack with a range of extra articles. It’s all thoughtful, thought-provoking stuff—and its all free. Find it at worksinprogress.news.

Show notes

* The three Scottish criminal cases:

* “Golf club thug spared jail over age”

* Community service not jail for rape (and the conviction later quashed)

* 3 year-jail sentence for rape

* The Scottish Sentencing Council guidelines from 2022

* The commissioned review by University of Edinburgh on brain maturation

* Useful 2022 Nature paper on structural “brain charts for the human lifespan”

* 2024 preprint on the lifespan trajectory of functional brain activation for cognitive control

* 2023 paper with 10,000 people aged 8-35 measured on executive function tests

* BBC Science Focus article by Dean Burnett on the “brain matures at age 25” idea

* “The myth of the 25-year-old brain” in Slate

* Stuart’s i article from last year on the Scottish Sentencing Council

Credits

The Studies Show is produced by Julian Mayers at Yada Yada Productions.