Inside the teenage brain

Why on earth did you do it?’ must be one of the most frequently posed questions to teenagers. The bright, ambitious boy standing before me is perplexed: prompted by a video clip online, he has liberally sprayed aerosol on his torso and then set fire to himself. There is a pause, then, ‘It seemed like a good idea at the time.’

In matters trivial, dramatic or, in this case, painful, teenagers seem to behave in bizarre ways. It is tempting for parents to believe that once our children reach adolescence somehow the huge gulf between childhood and adulthood has been bridged. We tend to believe that we are dealing with an individual who, although perhaps physically still undergoing some development, has a mature brain; lacking a little experience perhaps, but nothing that a sound secondary education cannot provide. In fact, nothing could be further from the truth. There are huge differences in the way that the adult and adolescent brains operate. Indeed, a teenager appearing to behave like a lunatic may just be a normal adolescent. At times it can seem as though this evolutionary process has been designed to cause maximum frustration to parents, yet such processes have been carefully selected to ensure a successful outcome for the child — and, though it can sometimes be hard to believe, also for the parent.

In the past 15 years there has been a dramatic increase in the neurobiological evidence available to support psychological investigation. In particular, a wealth of data is being produced by magnetic resonance scans, which throw light not only upon the structural transformations in the brain but also, by monitoring blood flow in the brain, on which regions are active when particular tasks are being performed.