Brakes off for the peer show
The typical teenager is too often portrayed as irrational and impulsive, making risky choices as they struggle to control their raging hormones and wayward emotions. But is this really the case? Do teenagers really lack the skills to guide and control their behaviour?
Executive functions, the processes that allow us to control and guide our thoughts and actions, continue to develop through our childhood. Research suggests, however, that these may mature by mid-adolescence.
Psychologists have used computer games to measure different aspects of executive function. They have found that by the early teens, teenagers are as good as adults at regulating their actions.
Teenagers can flexibly switch their attention between tasks to sort items by different features (such as colour and shape). They are able to suppress impulsive actions, measured by pressing left and right buttons in response to the corresponding arrows, but withholding the response when a signal is heard. They can also plan ahead to reach short-term goals, such as rearranging stacked-up discs or coloured balls in a specified number of moves.
All these skills are important in being able to guide and control choices and actions in new or difficult situations. So it seems that teenagers do possess the necessary skills to control their behaviour.
But in these laboratory-based situations, teenagers are performing these relatively abstract tasks on their own. And this is different to the social, emotional-charged situations they face in life.
In decision-making games, where choices result in either winning or losing points, adolescents have to learn by trial and error which choices to make. This kind of task taps into the more emotion-based reward system in the brain, and performance in these sorts of games continues to improve until the late teens, suggesting that the ability to deal with emotional situations takes longer to mature.
The picture is complicated further when peers are involved. A study by Gardner and Steinberg asked adolescents (13-16 years old), youths (18-22 years old) and adults (24 and over) to play a computer game in which they could choose to continue driving after a traffic light had changed to amber to earn more points. If the car was still moving when the lights turned red, they would crash. This game was played either alone or with two friends.
While there was no difference between the age groups in the number of risks taken when alone, adolescents took many more risks in the presence of their friends than adults or youths did. These findings show that studying interaction between executive functions and socio-emotional skills is extremely pertinent to understanding the teenage mind. However, more research is needed.
The frontal lobes of the brain are critical for executive functions. And different parts of the frontal lobes seem particularly important for different executive skills, such as keeping data in one's working memory, or suppressing an impulsive action. Functional magnetic resonance imaging (fMRI) is used to look at patterns of brain activity associated with different executive processes. This technique has shown increases in brain activity with age in the specific regions of the frontal lobes, and other parts of the brain, that support executive functions. This demonstrates that improvements in the ability to regulate behaviour are linked to developmental changes in the brain.
While it is often assumed that developments in the brain must come first and cause the improvements in behaviour, this is not the case. Experience and the environment affect the brain and the behaviour it supports. Pernille Olesen and colleagues at Stockholm's Karolinska Institute gave adults five weeks' practice on memory games, such as remembering lists of numbers and the location of a series of dots. This training improved the performance of their working memory. It also increased the brain activity in regions involved in this skill. This indicates that the teenage brain can be trained to make better choices.
It appears that teenagers have the skills needed to make well-informed decisions; although it may be more difficult for them to apply these in emotional situations, or when there is peer pressure. But it would be wrong to conclude that nothing can be done. There is the potential to learn. From studies like Olesen's, it is clear that teaching executive function skills could have a significant impact on teenager behaviour, and associated changes in the brain.
Executive strategies can aid decision-making processes, stopping people from rushing in without thinking, encouraging them to switch between alternatives, and to think about long-term consequences.
Raising teenagers' awareness of executive functions - what they are, how the brain regulates them, and how they can be applied to decision-making - may help them to deal more maturely with new social and emotional dilemmas
Dr Lucy Cragg is a research fellow in neuroscience at the Brain and Body Centre at Nottingham University
Next week: Professor John Geake of Oxford Brookes University on gifted and talented pupils
Gardner, M. amp; Steinberg, L. (2005). Peer influence on risk taking, risk preference, and risky decision making in adolescence and adulthood: An experimental study. Developmental Psychology, 41, 625-635.
Olesen, P. J., Westerberg, H., amp; Klingberg, T. (2004). Increased prefrontal and parietal activity after training of working memory. Nature Neuroscience, 7, 75-79.
Paus, T. (2005). Mapping brain maturation and cognitive development during adolescence. Trends in Cognitive Science, 9, 60-68.