Teenage risk taking and the social influence of friends may reflect maturing of the adolescent brain

Why do some adolescents take risks around dangerous driving, sexual behaviour and alcohol, yet shrink from taking a chance when it’s time to ask questions or speak up in class?

Research on adolescents’ brains and behaviour is beginning to yield some answers. The findings could have implications for education, criminal justice, mental health and other public policy areas affecting young people.

When we map adolescent brain development, we find that regions dedicated to processing emotion and reward mature earlier than regions that protect against social anxiety and inhibit risk-taking. In other words, adolescents can readily process the rewarding feeling that comes from taking a risk, but they are still developing the ability to stop themselves from taking risks.

This may explain why, even though adolescents might well understand the long-term risks of tobacco, drugs and alcohol, many young people still experiment with smoking and binge-drinking. A mismatch between elements in their brain development seems to make adolescents both more sensitive to positive emotional feelings and less inhibited about taking risks. Perhaps most important, this mismatch seems also to make them more prone to social influence and peer pressure, explaining why adolescents are more likely to take risks if their friends are around.

The picture emerging of adolescents is that they have a heightened desire to fit in with their peer group, and anxiety about social exclusion, plus sensitivity to emotional reward, all of which work in tandem with a less developed ability to inhibit risk-taking in certain contexts.

However, this alignment of different factors does not always occur in such a straightforward fashion. In the classroom, young people who are ready to take risks elsewhere may feel embarrassed about asking a question or presenting an answer for fear of derision from their peers. In short, in the classroom, the desire to be accepted by peers can trump a willingness to take risks.

“We would be wise to reframe adolescent behaviour as exploratory and potentially socially beneficial as opposed to only risky and problematic.”

Some of the recent advances in understanding typical adolescent behaviour come from brain imaging.

Until about 20 years ago, it was assumed that nearly all human brain development occurred during the first few years of life. We now know that development continues throughout adolescence and even into adulthood.

The prefrontal cortex, at the front of the brain, shows particularly striking and prolonged changes during adolescence. This area is responsible for a wide variety of complex behaviours, including decision-making and planning, interpreting how other people think and feel, and self-awareness.

Simulation experiments are shedding further light on adolescent behaviour. My research group has used a computer game that can simulate social exclusion and so helps us study the effects of social rejection at different ages.

Participants play a game with two other players over the Internet. The other players can either include or exclude the participant from the game. Using this game, Dr Catherine Sebastian in my research group demonstrated that adolescents – particularly younger adolescents – showed a greater decline in mood than adults did after experiencing simulated social exclusion.

Drs Lawrence Steinberg and Jason Chein have used driving simulations to look at the numbers of risks – such as accelerating through a changing traffic light – taken by people of different ages.

When adolescents and adults performed a driving task alone, they took similar numbers of risks. However, when a couple of friends were standing behind them, teenagers took three times as many risks, whereas adults continued to take the same number.

These findings fit with data showing that young drivers are more likely than adults to have car accidents and that the majority of accidents occur when there are passengers of a similar age in the car. They also exemplify how, in a peer group, young people may indulge in high-risk behaviour that they might eschew when alone.

This work on adolescent brain development raises three important issues, which I discuss in a recent paper, ‘Is Adolescence a Sensitive Period for Sociocultural Processing?’ co-authored with my colleague Kathryn Mills and published by Annual Review of Psychology.

First, we have had to revise our tendency to attribute typical adolescent behaviour chiefly to hormones and to changes in the social environment. It is clear now that behaviour is linked, at least in part, to biological developments in the brain that are adaptive, natural and inevitable.

Typical adolescent behaviours are probably advantageous in some way, since they are so intrinsically rooted in human development. It might be wise, therefore, to reframe adolescent behaviours as exploratory and potentially socially beneficial as opposed to only risky and problematic.

Speculatively, our understanding that adolescents tend towards different behaviours when among their peers might be a consideration in the continuing debates about levels of criminal responsibility for young people. For example, where young people are involved together in collective crimes, should the level of individual responsibility for each adolescent be judged as high as in a crime committed by a lone adolescent?

Second, the new insights from neuroscience might have important implications for mental health conditions, which often begin during the teenage years. Understanding changes in the brain may help to explain how these conditions develop.

Third, we should find ways to channel risk-taking. If adolescent behaviour is linked to approval from friends and to avoiding social exclusion, we should examine how young people might positively influence each other’s learning and decisions through peer education and mentoring. It would be worth testing whether peer-led initiatives might channel the natural propensity to take risks into positive contexts such as academic learning and career planning, where it would be advantageous.

Like adults of nearly every generation, Shakespeare dismissed the capacities of adolescence, declaring in “The Winter’s Tale”: “I would there were no age between ten and three-and-twenty, or that youth would sleep out the rest; for there is nothing in the between but getting wenches with child, wronging the ancientry, stealing, fighting.”

Today, thanks to the insights of the behavioural sciences and of neuroscience, we can explore how policy could focus on the strengths that come from adolescent development, not simply on teenagers’ developmental weaknesses.