For a long time, the period of adolescence was something of a mystery.

Much of what was written came from theoretical speculation, clinical or personal experience, or folklore. With the advent of more scientific advances, we can now understand some of the ways the brain develops during this period and how it underlies adolescent emotion, cognition and behavior.

The traditional view of adolescence holds that it is a time of storm and stress, when youth are very emotionally labile, prone to moodiness and even outright emotional outbursts. If you are a parent or a teacher, you may have been warned to be prepared for this. But is it true?

Of course, there are marked individual differences in temperaments and traits among adolescents. Not everyone goes through adolescence in the same way, as you have no doubt, experienced in your own family or with your own children. But taken as a group, there are some differences in emotionality between adolescents in general and both older/younger groups. Compared to these other groups, many studies of adolescents do show increases in sensitivity to emotionally-loaded messages and images. This sensitivity seems to be mediated by the physical and psychological changes of this period of development.

Emotional reactivity or emotionality has been studied by comparing the automatic responses of adolescence with those of individuals from different age groups. The collective results of this line of research do demonstrate greater pupil dilation to emotional pictures, suggesting automatic arousal, increased reports of daily negative or distressing emotions, a greater likelihood that neutral events in life are perceived as negative or threatening, and more significant interference of emotions with academic tasks than is the case for other age groups. So we may conclude that something is happening in the brain at this time that makes them different from younger children and adults. What is a plausible explanation?