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Teenage Brains: Why Do They Do What They Do?

The science behind teen behavior

It seems like every week there is another news story about alcohol and drug abuse, campus sexual assault, or risky behavior by college-aged people in America. As a neurologist and neuroscientist, and parent of now twenty-somethings, my antennae prick up every time I hear one of these stories. And it’s not just me - college officials are struggling to respond fast enough, and a rich national dialog is developing around these issues.

Why do things seem so out of control? Both of my kids experienced the deaths of several high school and college friends due to excessive drinking combined with driving or swimming. Back then we also read about the suicide of a Rutger’s student after his roommate used a concealed web cam to stream him having sex. That was a few years ago, and there continues to be a daily flow of college tragedies involving risk taking ranging from newsworthy stunts to criminal behavior.

How can such smart kids do such stupid things? There is no doubt that the teen and college years are sadly marked with bright kids doing seemingly irrational, self-injurious, violent and illegal things. What are they thinking? It’s clear that IQ is not the issue: many of these stories involve students that have excelled academically.

From a neurobiological standpoint, a partial explanation for all this risk taking is that the brain is not fully developed until the mid-twenties. Relevant to risk taking is the fact that the connections to the frontal lobe are not yet fully complete, and this is the area of the brain we believe is critical for “executive function”, namely judgment, empathy, and impulse control. Also, human and animal research shows that drugs and alcohol, especially binge drinking, can have a greater effect on the teen and early twenty-something’s brain than the adult brain. Combine this developmental propensity for lack of judgment with drugs and alcohol, and the result can be disastrous- and lethal at times. While the scientific explanation is recent, this period of teen brain development has always been around. Car insurance companies have known about it all along, and rates are astronomically high to cover the collisions that result from impulsive and inexperienced young adult drivers.

Behavior in this age group is in part a function of brain development but is also a function of the environment. As the biology of brain development hasn’t changed, it’s reasonable to consider whether our environment today may be fueling this apparent increase in risky behavior. Enter the digital world, with an internet that allows ready access to a font of knowledge that has revolutionized our lives. Teens and young adult brains learn at faster rates than adults. But is there too much of a good thing? The same enhanced synaptic learning that is an advantage for teens also makes them much more vulnerable to environmental cues- there’s learning there, too.

Websites like TotalFratMove or Tindernightmares tell stories of partying, reckless behavior and sex. Often, this behavior is glorified, and what’s more is these sites can be readily viewed by teens and preteens that are still in school- shaping their expectations for college life. It’s much more pervasive online compared to the past singular sources, like the “Animal House”. At a more extreme end the internet can offer step-by-step guides to methods for date rape, suicide, and drug experimentation. In addition, forums of social networking cause flash parties, easy access to illicit drugs, and a forum for compulsive streams of boastful self-reports.

Compared to prior generations of relatively protected teenagers, this generation is exposed to an unprecedented level of information, stimulation, and outside influence. Couple this rapid fire of cues, ideas, role models, with impulsivity and a still unformed capacity for judgment, and you get sort of a perfect storm.

This generation (and moreso for all those to come) has unprecedented access to tools such as facebook, twitter, instagram, blogs and snapchat, and opposed to prior teens, the impulsive decisions that teenagers make today – sexting, posting pictures of them drinking or using drugs, cyberbullying – can follow them around for the rest of their lives. The schoolyard prank of yesteryear can go now go viral around the globe. The carelessly posted sexting is permanently embedded in the internet for future employers to discover.

Colleges and universities are faced with a huge challenge. The tightly packed social scene further intensifies the situation where impulsivity can feed pack mentality and desensitization to offenses of social mores. Greek life is now under patrol at many institutions as it is sort of a culture medium for this kind of behavior: all ingredients are present. One ingredient, hard alcohol, is now being tightly regulated at Dartmouth starting in March. Will that be enough? It’s a start, but digital connectivity is a major factor that has to be reckoned with, and it’s not going away. Rather than merely lamenting the behavior, we need a dialog around how our digital world, as well as other factors, is influencing these still impressionable brains.

Frances E. Jensen, MD is Chair of the Department of Neurology at the Perelman School of Medicine, and author of the recent New York Times Bestseller, “The Teenage Brain: A Neuroscientist’s Survival Guide to Raising Adolescents and Young Adults” (Harper Collins, 2015).