What is this article about?

In this article, research on the development of social cognitive processes and structural and functional changes in the social brain during adolescence is reviewed.

As individuals age, the brain changes in terms of gray and white matter volume, surface area, and cortical thickness. During childhood, cortical gray matter increases and in late childhood this reaches a peak. Later it declines, and it stabilizes as individuals reach their mid-20s. There is also a linear increase in white matter volume across childhood and adolescence.

Brain development also seems to be influenced by sex hormones, which control the onset of and progression through puberty. For instance, pubertal maturation is related to developmental changes in subcortical brain volume. The neural and psychosocial changes that are related to puberty can also lead to mental health vulnerabilities. The latest maturing brain regions are within the ‘social brain’, which is related to recognizing, understanding, and interpreting social cues from others. These include the dorsomedial prefrontal cortex, anterior cingulate cortex, inferior frontal gyrus, posterior superior temporal sulcus, anterior temporal cortex, amygdala, and anterior insula. Some of these regions are also involved in ‘mentalizing’, which is the ability to interpret the mental states of others. Studies have shown that regions within this social brain show a protracted structural development. For instance, the amygdala increases with 7% in volume between late childhood and mid-adolescence. After 14 years of age, there are no significant changes.

During adolescence, there are also significant functional maturations of regions that are involved in social cognitive processes. This means that during adolescence, mentalizing, social cognition, executive functioning, and emotion regulation skills all develop until adulthood is reached.

What do we know about mentalizing?

Mentalizing is the ability to understand and predict other people’s behavior. It has been suggested that adolescents, relative to adults, use different cognitive strategies when they think about other’s intentions.

Taking other people’s perspectives is important, especially when integrating into new social contexts (which happens during puberty), and when choosing peers to be friends with. One study has shown that both adolescents and adults recruit the dmPFC when taking someone else’s perspective into account, but when there were no social cues present, only adolescents also recruited the dmPFC. This means that adolescents also recruit mentalizing brain regions, when this not required.

The ability to mentalize is still maturing during adolescence, with children and adolescents making more errors than adults on perspective-taking tasks. Inhibitory control has also been pointed to as a contributor to these differences, which is also still maturing during adolescence.

It has also been shown that adolescents who perform poor on perspective taking tasks are more likely to report loneliness and peer rejection. In one study, reduced mentalizing was also related with the severity of depression. According to the stress-reward-mentalizing model, child and adolescent depression emerges from the interaction among impairments in stress-regulatory, reward, and mentalizing systems.

What about emotion regulation?

Adolescents who are accepted by their peers show more adaptive emotion regulation and are at lower risk for internalizing symptoms. The protracted development of the PFC (important for emotion regulation) may lead to that adolescents are less able to regulate their emotions, which increases their risk for anxiety- and stress-related disorders. Emotion regulation thus develops with across adolescence. The ability to mentalize is an important factor in the development of adequate emotion regulation abilities. Individual variations in emotion regulation may contribute to risky decision making in the presence of peers. Poor emotion regulation is also associated with more participation in risky behaviors.

What about the social risk of rejection?

Adolescents are more likely to take risks than adults when peers are present, and they are also hypersensitive to social rejection, and they are more likely to take health and legal risks in the presence of peers, to avoid this social rejection. Social rejection has been related to disruptions in emotion regulations, and is a risk factor for adolescent-onset mood disorders such as depression and anxiety. For example, adolescents can engage in smoking when this is the peer group norm, to avoid the risk of rejection, even when there are health and legal consequences. This is not always irrational; sometimes it does really help to engage in these risky behaviors to be accepted by the peer group.

What about peer influence on prosocial behavior?

Peers can also have a positive influence on prosocial decisions. For example, when adolescents observe that their peers volunteer, they are more likely to also volunteer. Adolescents are also more likely to be influenced by others toward prosocial behaviors compared to adults. High-status peers and close friends are more influential. Prosocial risk taking, for example standing up for someone who is being bullied, is not related to harmful risk-taking such as reckless driving and drug taking. Instead, it is associated with lower reward sensitivity, higher punishment sensitivity, and greater school engagement. Thus, positive risk taking seems to be beneficial for adolescents.

What can be concluded?

Adolescents are thus vulnerable to mental health problems, and risk factors in their social environment such as peer rejection contributes to this vulnerability. Interventions that aim to improve the vulnerability toward poor mental health may focus on improving prosocial behavior and emotion regulation abilities.