Sarah-Jayne Blakemore: The mysterious workings of the adolescent brain (2)
Okay, so if I just show you the percentage errors in a large developmental study we did, this is in a study ranging from age seven to adulthood, and what you're going to see is the percentage errors in the adult group in both conditions, so the gray is the director condition, and you see that our intelligent adults are making errors about 50 percent of the time, whereas they make far fewer errors when there's no director present, when they just have to remember that rule of ignoring the gray background. Developmentally, these two conditions develop in exactly the same way. Between late childhood and mid-adolescence, there's an improvement, in other words a reduction of errors, in both of these trials, in both of these conditions. But it's when you compare the last two groups, the mid-adolescent group and the adult group where things get really interesting, because there, there is no continued improvement in the no-director condition. In other words, everything you need to do in order to remember the rule and apply it seems to be fully developed by mid-adolescence, whereas in contrast, if you look at the last two gray bars, there's still a significant improvement in the director condition between mid-adolescence and adulthood, and what this means is that the ability to take into account someone else's perspective in order to guide ongoing behavior, which is something, by the way, that we do in everyday life all the time, is still developing in mid-to-late adolescence. So if you have a teenage son or a daughter and you sometimes think they have problems taking other people's perspectives, you're right. They do. And this is why.
So we sometimes laugh about teenagers. They're parodied, sometimes even demonized in the media for their kind of typical teenage behavior. They take risks, they're sometimes moody, they're very self-conscious. I have a really nice anecdote from a friend of mine who said that the thing he noticed most about his teenage daughters before and after puberty was their level of embarrassment in front of him. So, he said, "Before puberty, if my two daughters were messing around in a shop, I'd say, 'Hey, stop messing around and I'll sing your favorite song,' and instantly they'd stop messing around and he'd sing their favorite song. After puberty, that became the threat. (Laughter) The very notion of their dad singing in public was enough to make them behave.
So people often ask, "Well, is adolescence a kind of recent phenomenon? Is it something we've invented recently in the West?" And actually, the answer is probably not. There are lots of descriptions of adolescence in history that sound very similar to the descriptions we use today.
So there's a famous quote by Shakespeare from "The Winter's Tale" where he describes adolescence as follows: "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." (Laughter) He then goes on to say, "Having said that, would any but these boiled brains of nineteen and two-and-twenty hunt in this weather?" (Laughter) So almost 400 years ago, Shakespeare was portraying adolescents in a very similar light to the light that we portray them in today, but today we try to understand their behavior in terms of the underlying changes that are going on in their brain.
So for example, take risk-taking. We know that adolescents have a tendency to take risks. They do. They take more risks than children or adults, and they are particularly prone to taking risks when they're with their friends. There's an important drive to become independent from one's parents and to impress one's friends in adolescence. But now we try to understand that in terms of the development of a part of their brain called the limbic system, so I'm going to show you the limbic system in red in the slide behind me, and also on this brain. So the limbic system is right deep inside the brain, and it's involved in things like emotion processing and reward processing. It gives you the rewarding feeling out of doing fun things, including taking risks. It gives you the kick out of taking risks. And this region, the regions within the limbic system, have been found to be hypersensitive to the rewarding feeling of risk-taking in adolescents compared with adults, and at the very same time, the prefrontal cortex, which you can see in blue in the slide here, which stops us taking excessive risks, is still very much in development in adolescents.
So brain research has shown that the adolescent brain undergoes really quite profound development, and this has implications for education, for rehabilitation, and intervention. The environment, including teaching, can and does shape the developing adolescent brain, and yet it's only relatively recently that we have been routinely educating teenagers in the West. All four of my grandparents, for example, left school in their early adolescence. They had no choice. And that's still the case for many, many teenagers around the world today. Forty percent of teenagers don't have access to secondary school education. And yet, this is a period of life where the brain is particularly adaptable and malleable. It's a fantastic opportunity for learning and creativity.
So what's sometimes seen as the problem with adolescents — heightened risk-taking, poor impulse control, self-consciousness — shouldn't be stigmatized. It actually reflects changes in the brain that provide an excellent opportunity for education and social development. Thank you.