Teenagers who cannot get off the couch. Not wanting anything. Go to bed late. Being impulsive. And sometimes you can’t choose. Young people who only think about themselves. Or take their friends into account. And ashamed of their parents. In short: there is not much you can do with teenagers. This is one way of looking at adolescence. But you can also see it differently. After all, the brains of adolescents are working hard to lay the foundation for healthy adulthood. The frontal cortex in particular is only at full strength when young people are in their mid-twenties. And that explains a lot of the typical ‘adolescent behavior’. It has long been thought that the brain grew and developed only during childhood. Thanks to all kinds of modern research methods, we now know that this is not the case. The brain continues to develop well beyond the teenage years. Some parts of the brain even last until people are in their 20s or 30s. But it is precisely in those teenage years that we also see brain development reflected in the behavior of young people. This is remarkable, because adults may think of these years as when adolescents stand still and throw away their chances of a good adult life. Fortunately, that is not the case. The vast majority of adolescents grow up to be nice adults.
- What is adolescence?
- When are you an adolescent?
- What are you like as an adolescent?
- What does adolescence look like in the brain?
- Brain growing
- White and gray matter
- Glial cells
- Neurotransmitters
- Typical teenage or adolescent behavior
- How do you become yourself?
- Risky behavior
- Executive skills
- Development continues
What is adolescence?
There is no general consensus on a definition of adolescence or on exactly how long this period lasts. Some even think that adolescence is a made-up concept. However, there is indeed something qualitatively different about the brain during adolescence compared to that in childhood and adulthood. Although the generation gap that is sometimes assumed to be fixed is absolutely not a requirement and also seems to be culturally determined. We also do not see possible problem behavior in all young people . But even then, that behavior requires understanding rather than condemnation or ridicule of young people for whom these times can be very difficult.
When are you an adolescent?
It is common to say that adolescence starts at puberty and ends when people have somewhat gotten their lives on track. Adolescence therefore has a biological beginning and a social end. But both milestones are (also) culturally determined and can change over time. In Western countries, adolescence may last the longest, because puberty starts earlier and earlier (as a result of the fat percentage required for this that is reached earlier) and young people start living independently later, because young people live at home longer, study longer and, because the moment when they get into a permanent relationship and/or find suitable work takes longer. On average, adolescence in Western countries is the period from about 13 to 25 years.
What are you like as an adolescent?
Adolescence can be a difficult time. As a young person you are mainly searching. Searching for your own identity. You are no longer a child, but you are not yet an adult either. Sometimes that also means that you can be unpredictable and do things and make choices that you did not expect to make. You can be impulsive or risky. You don’t know yourself yet. You are not yourself yet. But you are also looking for the other. You want to learn to understand the other person and belong, and above all not to be left out. These two developments go hand in hand and reinforce each other. This also applies to the interaction between environmental factors, such as family, friends and school, and internal factors, such as the brain and the endocrine system.
A lot happens during adolescence: you make many choices, experience (consciously) many things for the first time, visit new schools (secondary education, secondary vocational education or higher education ), your (sex) hormones peak and your brain changes.
What does adolescence look like in the brain?
The human brain consists of a complex network of nerve cells or neurons. It’s not like people’s brains grow steadily until they’re done. You could even say the opposite.
Brain growing
The brain of mammals, and therefore also of humans, has come up with something clever to become the best brain possible. A ‘fight’ takes place for the best nerve cells. In order to have as much choice as possible, the neurons are overproduced: many more are made than necessary. After the best cells have won, they go to the right place in the brain and form connections with each other. The unselected cells die according to a fixed program by genes that are activated and cause these cells to shrink and die, after which the material is recycled.
So a baby has many more neurons than an adult. Because the very best neurons remain through this process of overproduction and competitive pruning, much better connections between the synapses of these cells are possible. But that also means that the connections are only optimal in an adult brain. And only when the connections are optimal can communication excel.
White and gray matter
The brain consists mainly of white matter and gray matter. The gray matter consists of the neurons already mentioned. You could say this is where the thinking happens. The white matter contains the long extensions or nerve fibers (the axons) of the neurons. These are surrounded by myelin, a white fatty substance. Hence the name: white matter. We call a bundle of axons a nerve. They provide the connections between the different neurons. An adult brain has an average of about 86 billion neurons. A neuron has an axon and several dendrites; the short spurs. White matter increases during adolescence, making the brain faster and more efficient, while gray matter decreases due to significant cuts in the number of neurons. This pruning is partly influenced by the environment. Everything can influence the end result: your diet, the extent to which you exercise, whether you drink alcohol, which school you go to, which friends you have, which family you grow up in and what experiences you have during adolescence. An important period for the development of your brain!
Glial cells
In addition to nerve cells, our brain also contains glial cells or support cells. They support the function of the brain by, among other things, ensuring smooth communication between different nerve cells, promoting the speed and efficiency of information transfer between neurons (oligodendrocytes), and ensuring recovery in the event of damage (astrocytes). and by fighting any infections and other potentially harmful substances (microglia). There are approximately as many neurons as glial cells in the human brain.
Source: Wellcome collection
Neurotransmitters
Of course, communication between neurons does not take place by talking to each other. Instead, connections, or the transmission of electrical signals, take place by exchanging chemicals. These substances are called neurotransmitters. Neurotransmitters ensure that neurons can communicate with each other. Calcium ensures that the neurotransmitters are fired from the synapse, the end and therefore the contact point of the neuron. The neuron that sends the ‘message’ is called a pre-synaptic neuron. The neuron that receives the message with the help of receptors is called post-synaptic neuron. Because the post-synaptic neuron then sends a substance back, the pre-synaptic neuron stops sending neurotransmitters. Depending on the neurotransmitter, the post-synaptic neuron can transmit it further or prevent it from spreading further. So everything you feel, experience; all your desires and needs have their origins in the brain, the interaction with hormones and the communication between the different parts of the brain.
Typical teenage or adolescent behavior
Teenagers are known for valuing the opinions of their peers over those of their parents or other adults and for being very, very aware of themselves. They often seem more impulsive and may be more likely to take risks. Finally, they are less good at understanding, regulating and organizing their emotions and actions (the so-called executive functions). These behaviors all trace back to brain development during these important formative years.
How do you become yourself?
Your genes predispose to who you can be (your genotype). Together with your experiences and your environment, you become who you are (in biological terms: the phenotype). Your appearance, your personality, your temperament, your intelligence, your family, your friends, your school, your clubs, and so on. Everything makes you your unique self. In childhood, the sense of self, the sense of self, continues to expand. As a baby you do not yet have a sense of yourself, but by the time you are two years old you recognize yourself and you become increasingly aware that you go through life separately from others. But during adolescence you become aware that all actions and choices contribute to your self-image. And the image that others have of you. What music you listen to, what clothes you wear, which political party you vote for, which study you choose, who your friends are. Everything makes you yourself. And also determines how you relate to others.
Research shows that adolescents, much more than adults, react hypersensitively to social exclusion. They react much more strongly than adults. So it does so much more. Adolescence focuses on developing the social self. You break away from your parents and start building your own life. You are also dependent on others for this. During adolescence you can be very concerned with yourself and very aware of yourself. This is because you cannot yet reflect on yourself properly. You develop metacognition or introspection by analyzing your own thought and feeling processes. This gives you insight into the emotions that guide your actions. And you learn to estimate how certain you can be whether you are doing and knowing the right thing, which will help you feel more and more confident. During adolescence, this sense of self-confidence increases until it remains stable in adulthood. Self-knowledge arises from the knowledge you build up about the way you react in different situations. Just as you still have to get to know yourself, you also have to get to know the other person and learn to assess the other person’s reactions to you. Young people are getting better at reading facial expressions. As a young adolescent you are not very good at this yet. That makes you even more insecure. But by watching each other a lot and learning from each other, you become better and better at it. The focus on peers therefore has an important function.
Risky behavior
Young people are just as good as adults at assessing risks and they know that they are not invincible. Yet they are more likely to show risky behavior than children or adults. This is evident, among other things, from Sarah-Jayne Blakemore’s book ‘Inventing Ourselves’ from 2018. Especially in situations where they are with friends or where emotions run high. When it comes to risk behavior, young adolescents (12-14 years old) in particular are the most influenced of all age groups by peers (peer pressure) compared to the influence of adults. Young adolescents therefore mainly look at what their friends and peers think of something. Whether it concerns smoking, drinking alcohol or bullying. Young people aged 19 to 25, 15 to 18 year olds and the group of adults (19 to 59 years) are slightly more influenced by adults than by peers. Children are influenced most by adults. It is striking that all age groups adapt their behavior under the influence of others. This applies most strongly to young people up to the age of 26, but research shows that we are all influenced by other people. This once again confirms the notion that we are social beings who need each other.
Executive skills
The prefrontal cortex ensures that we can influence our behavior through experiences and learning and that we can (learn to) assess and evaluate situations. It is said that self-awareness comes from this part of the brain. The prefrontal cortex is located in the front part of the frontal lobe, just behind your forehead. It is involved in higher cognitive functions (executive skills), social interaction and self-awareness. Executive skills refer to the brain’s regulatory functions to plan, organize, resist impulses and regulate your emotions and behavior.
This prefrontal cortex becomes smaller during adolescence, as a result of the aforementioned pruning, and therefore more efficient. Because the prefrontal cortex is not yet fully developed, adolescents are not yet as good as adults in executive functions and it also takes longer to do some things. easy to process. For example, that is where indecision and difficulty choosing come from. And there are quite a few decisions, big and small, that you have to make every day. It appears that adolescents use a different strategy to make decisions, also because other brain areas are active when making decisions, MRI scans show.
The development of non-verbal reasoning also develops during adolescence (the ability to understand and analyze visual information): young people in late adolescence are better at this than young people in early adolescence (but not better than adults). This argues for extra attention to training, especially in these later years and not as it is now with young adolescents.
Development continues
It is becoming increasingly clear that our brain is plastic and is not already formed in childhood. Our brains continue to develop and adapt throughout our lives. But during adolescence the brain is subject to many changes due to brain maturation and the associated development of awareness of self and other. It is also a time of many new experiences and emotions. And that also makes it an important period.
Nowadays we are all aware that the first three years of a human life are a critical period. The research of Sarah Jayne Blakemore and others suggests that the same could be true of adolescence. And so it is important to want and be allowed to change during this period. With everyone’s attention and understanding.