The “social brain”
Neuroscientist Sarah-Jayne Blakemore studies “the social brain”- the brain functions we use to understand and interact with other people. In her talk about the adolescent brain, she explains what we have all observed at one point or another in our lives: that adolescents can act pretty strange from time to time. They take risks without considering the consequences, they don’t plan ahead, they are moody, and they are very self-conscious. Recognize yourself? Despite not being a teenager anymore? Don’t worry. Chances are you still qualify as an adolescent.
Adolescence is, psychologically speaking, the life-span between the beginning of puberty and the mid-twenties. “The brain continues to develop right throughout adolescence and into the 20s or 30s.”, Blakemore explains. So, what happens to us brainwise during this time? It seems that puberty starts with a peak of gray matter volume, and progresses with a decrease of this very same brain matter. While girls’ grey matter volume peaks between 10-12 years, boys’ grey matter do so when they are 12-14 years old.
In her studies, Blakemore especially looks at the prefrontal cortex (the front part of our brain), which is much bigger in humans than in other species. This is the part of the brain where all the typically “adult” stuff is happening: decision-making, planning, inhibiting inappropriate behavior, being able to emphatically understand other people, and self-awareness.
The fine-tuning of brain-tissue
Blakemore found that this brain region undergoes substantial development during adolescence. At the beginning of puberty the gray matter in the prefrontal cortex increases and after early adolescence this brain matter decreases to eliminate unwanted synapses. “Synapses that are being used are strengthened and synapses that aren’t being used in a particular environment are pruned away.”, Blakemore explains. So, it’s especially in this period of life that we need to be in a stable and nurturing environment, so that we have a shot at a healthy development. Blakemore describes it as a “fine-tuning of brain tissue according to the species-specific environment”.
Blakemore’s research also found that not only brain matter, but also brain activity, decreases during adolescence. This happens particularly in the “social brain” (in the medial prefrontal cortex, to be exact). This part of the brain is responsible for understanding other’s feelings and thoughts; being able to put oneself in someone else’s position. So, this is basically where our empathy is located.
Turns out that these very important brain functions which determine how skilled we are with our social behavior, are not fully developed yet. At least, not until we’re 25, and even then, potentially not until we’ve reached our early 30s. “The ability to take into account someone else’s perspective, in order to guide ongoing behavior, is still developing in mid-to-late adolescence.”, Blakemore explains. This means: Yes, adolescents do have problems taking other people’s feelings and thoughts into account. Even people in their twenties do. And yes, this is normal. (But also remember that this, at some point, stops being normal, and then you might consider doing something about it.)
Find out about all the mysterious workings of your brain in every stage of adolescence in this enlightening and enchanting TED Talk.