A new scientific study suggests that teenagers use a different part of their brains than adults to make decisions, resulting in a kind of selfishness. University College London neuroscientist Sarah-Jayne Blakemore asked people of various ages decision-making questions and questions about the well-being of others. In teenagers, the superior temporal sulcus lit up. In adults, the prefontal cortex was more active. From New Scientist:
The superior temporal sulcus is involved in processing very basic behavioural actions, whereas the prefrontal cortex is involved in more complex functions such as processing how decisions affect others. So the research implies that "teenagers are less able to understand the consequences of their actions", says Blakemore.
In (one) experiment, Blakemore asked 112 participants (aged from 8 to 37) to make decisions about other people's welfare and timed how long it took them to respond. The questions included: "How would your friend feel if she wasn't invited to your party?"
She found that the response time got shorter as the participants got older, suggesting that the older people found it easier to put themselves in other people's shoes.
Blakemore suggests that both findings might be explained by an evolutionary mechanism in which the development of the brains of adolescents takes precedence over its performance. "You don't need to be on a par with other people because you are looked after until reproductive age. Only then do you need to start to take into account other people's perspectives."
