The Myths about the Teenage Brain

Elena Blanco-Suarez, Ph.D.
3 min readMar 20, 2019

Cognitive abilities (working memory, digit span and verbal fluency) seem to be fully developed at age 16 or 17. Emotional and social skills need to be developed to reach prosocial adulthood. However, everyone knows that teenagers (being considered between 13 and 17 years of age) are irrational, make poor decisions and take unnecessary risks. But is this true?

The Teenage Brain

Usually, we think that teenagers are irrational and have a difficult time making good decisions, or that they have no self-control. However, this is not completely true. In fact, teenage brains can perform like adults at certain decision-making tasks, but teenagers appear to be heavily influenced by the context, compared to adults or even children.

At a task that required exercise self-control, teenagers performed remarkably worse than adults when these tasks were in emotional contexts, this is when decisions had to be made quickly and in the heat of the moment. Research suggests that this could be caused by the fact that circuits involved in motivation and emotions develop earlier than those in the prefrontal cortex, the brain region that is in charge of control. Connections between these different areas strengthen later in life, reaching fully maturity in adulthood.

During performance of this task, researchers observed by brain imaging that there was an increased activity of the ventral striatum, a brain region involved in reward processing, whereas the region in charge of control processing, the prefrontal cortex, seemed to be much less active.

Another decision-making task that teenagers failed was the Stoplight task: You are driving and encounter a traffic light that turns to yellow, do you speed up to go through, or you slow down to stop at it? Adolescents performed just as well as adults when they were on their own performing the test, choosing the least risky option. However, when they were watched by their peers, more often they decided to speed up and try to make it through the light before this turned to red. It was peer pressure that made them take higher risks.

Some studies show the tendency of teenagers to embrace threat rather than avoiding it. In addition, teenagers seem to crave peer approval and pushed by peer pressure, which may explain why teenage criminal offenders tend to be in groups rather than acting alone.

The Importance of Having an Adult Brain

Researchers, using different tests like the ones mentioned above, conclude that performance maturity is rather reached at a later age, 21 or 22 years of age, which is what nowadays in the US is considered old enough to do certain activities such as drinking. However, other important activities as driving and voting are allowed at a younger age, at which neurological maturity may still be under construction. These patterns though are found not only in American youth, but other countries around the world, suggesting that it has biological components, like genetics, and it is not purely cultural.

Adolescents, just like adults, are all different and some will face more trouble at adapting than others, making better decisions or exercising self-control. However, research on the adolescent brain is necessary as establishing brain maturity is crucial to shape policies and determine when the human brain has fully cognitive ability to be responsible for its own actions and the consequences that come with them.

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Elena Blanco-Suarez, Ph.D.

Neuroscientist, science communicator, ukelele player. I write about brains and sometimes other stuff.