Teenagers' tantrums: it's all in the brain

Sulky teenagers cannot help being rude or having tantrums because their brains have not yet fully developed, a leading neuroscientist said yesterday.

Sarah-Jayne Blakemore, a cognitive neuroscientist at University College London, said that they could not help being sullen because they were still developing social skills and did not yet have the full mental hardware to see the world from someone else's point of view or predict the consequences of their actions.

Dr Blakemore, who presented the work at the British Association festival of science yesterday, said it was questionable whether teenagers were mentally ready to be held responsible for their actions - in court, for example. "If making decisions about how you treat teenagers ... you need to take this new research into account," she said. "The brain is pre-programmed to undergo huge changes during adolescence."

Her research shows adolescents use their brains differently for tasks which involve putting themselves in someone else's shoes. "It's not just hormones causing teenagers to be difficult. It is also the fact that their brain is developing," she said. "It does give them a bit of an excuse."

In one study, she compared the responses of 112 adolescents and adults to questions that involved taking someone else's perspective on an event. She found that participants got quicker with age.

Next, her team looked at what is going on in the brain by putting 11 adults and 19 adolescents under a brain scanner. They asked questions that involved the subjects working out how they would solve a problem in the future - something that demands the ability to take the perspective of their future state of mind.

The brain activity was subtly different in the teenagers compared with the adults. The teenagers used a region at the front of the brain less and one at the back more. The latter region is involved in simply representing physical actions rather than social consequences or intentions, suggesting that the teenagers were thinking about the problem in a less sophisticated way.