What happens with hyperrational thinking is not a lack of thought or reflection as happens with impulsivity, and it’s not a matter of merely being addicted to a particular behavior or something we are ingesting. Instead, this cognitive process comes from a brain calculation that places a lot of weight on the positive outcome and not much weight on possible negative results.
By weight I mean that the evaluation centers of the brain downplay the significance given to a negative result. The scales that teens use to weigh out their options are biased in favor of the positive outcomes. Pros far outweigh the cons, and quite simply, the risk seems worth it.
This positively-biased scale can be activated especially when teens hang out with other teens or believe their friends will somehow observe their actions. The social and emotional context we experience as teens sets the stage for how our brains will process information. While that’s true for any person whatever their age, the influence of peers is especially strong during adolescence. Katey’s behavior was not impulsive—she planned her evening long ago in a hyperrational way.
This is not as simple as saying that teens are just impulsive. And it’s also not as simple as saying, “Oh, raging hormones,” as its sometimes stated. Research suggest that risky behaviors in adolescence have less to do with hormonal imbalances than with changes in our brain’s dopamine reward system combined with the cortical architecture that supports hyperrational decision-making—creating the positive bias that is dominant during the teen years.
In recent years, surprising discoveries from brain imaging studies have revealed changes in the structure and function of the brain during adolescence. Interpretations of these studies lead to a very different story than the old raging-hormone view of the teenage brain. A commonly stated but not-quite-accurate view often presented by the media is that the brain’s master control center, the prefrontal cortex, at the forward part of the frontal lobe, is simply not mature until the end of adolescence. This “immaturity” of the brain’s prefrontal cortex “explains immature teen behavior.” And this notion also explains why rental car companies generally won’t let someone younger than 25 take out a car. But this simple story, while easy to grasp, is not quite consistent with the research findings and misses an essential issue.
Instead of viewing the adolescent stage of brain development as merely a process of maturation, of leaving behind outmoded or non-useful ways of thinking and transitioning to adult maturity, its is actually more accurate and more useful to see it as a vital and necessary part of our individual and our collective lives. Adolescence is not a stage to simply get over, it is a stage of life to cultivate well. This new and important message, inspired by emerging sciences, suggests that the changes that occur in the adolescent brain are not merely about “maturity” versus “immaturity,” but rather are vitally important developmental changes that enable certain new abilities to emerge. These new abilities are crucial for both the individual and our species.