“A highly adaptable organ that allows us to make sense of the world”

Neuroscientist Lutz Jäncke talks about the major changes that take place in the brain during puberty and what they mean for our interactions with young people
Lutz Jaencke (KEYSTONE/Walter Bieri)
Lutz Jaencke (KEYSTONE/Walter Bieri)

Eveline von Arx: In a discussion with young people about death, one boy made the following comment: “If we lived forever, we wouldn’t have to set any goals.” What’s your reaction to that?

Lutz Jäncke: People have thought about death since the dawn of human history. But our brain isn’t well suited to thinking in terms of infinity. It’s more than we can handle. The brain needs clarity and structure.

EvA: What does that mean?

LJ: The human brain evolved over time. It is a highly adaptable organ that allows us to learn and make sense of the world around us. We have our own individual ways of interpreting the world, and we construct our future and our past. An interesting thing about the boy’s comment is that it came from a teenager, someone who is still growing and developing as a person. And development always means finding a sense of purpose. We can’t move in a multitude of different directions at once. This is absolutely crucial during adolescence.

EvA: Why?

LJ: Because adolescents need to learn how to find their place in their culture. To do so, they need certain rules and parameters. They have to find out where the limits are, and naturally they will test those limits. This holds true for any mammal, by the way.

“We have our own individual ways of interpreting the world, and we construct our future and our past.”

EvA: Coming back to the human brain: What changes occur in the brain during puberty?

LJ: The teenage brain undergoes a very specific maturation process, particularly with regard to the frontal cortex. Its volume increases substantially up to the age of somewhere between 11 and 14. That area of the brain plays an important role in what we call executive functions – the ability to control emotions, plan ahead and pursue goals. Because their brains are immature and undergoing significant changes, adolescents are less able than adults to concentrate for long periods of time and avoid being distracted. Moreover, there is a dramatic increase in networking in the teenage brain. Which network and which connections are formed and modelled is critically important. It matters, therefore, whether an adolescent spends hours playing computer games or practicing Bach fugues.

EvA: Why?

LJ: Our brains are plastic – which means that they can be altered by environmental influences. To put it simply, the neural connections that are used most are the ones that are sustained. Connections that are not used on a regular basis become less and less efficient – in keeping with the motto “use it or lose it.” So when adolescents make frequent use of the neural networks that are involved in controlling attentiveness and self-discipline, those networks will naturally be sustained or even expanded. If they aren’t used, we can assume that they will deteriorate. Consequently, performing challenging tasks that require a great deal of attentiveness and self-discipline strengthens the networks that play a key role in controlling attentiveness and self-discipline.

EvA: What do adolescents need during this phase?

LJ: Norbert Bischof has clearly demonstrated that all mammals, including humans, have two complementary systems of motives: One reflects a need for attachment, the other a need for stimulation. Attachment is a very strong motive for small children, who are less motivated by the desire for stimulation. This changes over the course of development. During puberty, the importance of attachment declines as the desire for stimulation increases. Adolescents are thrill seekers. This is why, from our adult perspective, they seem to behave in such strange and irrational ways. We need to show understanding, but we also need to remember that we should, and can, channel their desire for stimulation to some extent.

EvA: How can we do that?

LJ: We human beings have the ability to suppress our desire for a reward. We are capable of denying ourselves an immediate reward and working to achieve a long-term goal, even if we don’t know for certain whether a reward will ever come. The frontal cortex plays an essential role in this process. If it is not yet fully developed, as is the case in adolescence, parents and teachers need to set certain limits, within the framework of a solid relationship.

“Children should be given more opportunities to experiment and test themselves.”

EvA: Can you explain irrational teenage behavior?

LJ: During adolescence, a desire for stimulation becomes much more pronounced, hormonal changes occur, and brains undergo profound changes. So it is almost impossible for teenagers to control their emotions. It would be pathological if an adult were to exhibit such excessive enthusiasm. It would amount to abandoning one’s very self, since people who show such extremes of emotion don’t really know who they are.

During adolescence, their ability to reason is already quite well developed. The teenage brain is capable of reflection, but because life experience is lacking, it has not yet accumulated a great deal of knowledge. As a result, it looks for something to hold onto, something that will allow the teenager to comprehend and interpret the world. A celebrity like Justin Bieber can serve that purpose. The important thing is that he is not the only point of reference. What young people experience at home, with friends, at school plays an important role. While much of what they are learning is implicit, rather than conscious, the brain records their experiences and uses them to make sense of the world. Young people are open to anything that helps them find their way in the world.

EvA: Does it make sense to try to teach values to adolescents?

LJ: Definitely, and specifically through education. Educating children and adolescents is crucial. And I should note that education is not the same as training. It is very important to teach young people values in the subjects of history, philosophy and literature. That helps them learn to think. Literature, for example, can teach teenagers a great deal about human beings. It allows us to experience events vicariously and helps us learn to understand and interpret human behavior. During puberty, individuals are very sensitive to this kind of learning. In addition, children and adolescents like to learn things that they find enjoyable and that are relevant to their lives. I would like schools to be more geared to the needs of adolescents.

EvA: What would that mean?

LJ: Children should be given more opportunities to experiment and test themselves – through music, theater, sports. Acting in a play, for example, might involve memorizing lines in a foreign language. And it allows them to practice expressive communication. It’s also an opportunity to learn to portray a certain role convincingly. This is a way to teach about art and culture. But it shouldn’t be about grades.

EvA: Do learning experiences of this kind affect the development of executive functions?

LJ: Yes. When teenagers are working on a musical piece at home, for example, they have to schedule practice sessions. They learn to concentrate and to coordinate with their peers. All of these are important metacognitive skills.

Dr. Lutz Jäncke is a professor of neuropsychology at the University of Zurich. One of his research interests is brain plasticity, particularly in the context of education and learning.