Are Teenagers Responsible?

*This is the fourth and final in a series of blogposts about the teenage brain written by experts associated with The Massachusetts General Hospital Center for Law, Brain, and Behavior (CLBB). 

Ask any parent of a teen whether his or her child is responsible and a wry smile will appear.

If you could see the internal images and memories behind that smile, they would look like this: wet towels on the floor, a car left without gas on a workday morning, a forgotten homework assignment, a broken curfew.

Responsible? Of course not! Generally, most kids expect parents to take care of these mundane duties. And, for the most part they do. But what if the poor planning and irresponsibility involve high stakes and high risks? What if they involve life and death? The same parents who give knowing smiles also stay awake nights worrying that their adolescent and young adult children will drink and drive or worse. Why design such a foolhardy species? Why are young human beings prone to volatile emotions, thrill seeking and a seeming inability to think about the long-term consequences of what they do? Though it seems paradoxical, actually counter to survival of the species, from an evolutionary standpoint, this is just what we need them to do.

Evolutionary biologists understand that propagation of the species is the powerful imperative behind risk taking. The young of a species has to bravely venture out away from a comfortable nest with reliable food and nurturing to seek mates (ideally with a new gene pool) conquer obstacles and feel secure and invincible in hostile terrain.

How would you design such a brain that sets the youngster up to confront these challenges? You would make it temporarily less sensitive to danger, and more responsive to rewards and thrills. Modern neuroscience is demonstrating that the teen behavior we all observe has a brain signature that can be scanned – pictures that show the exaggerated preferences that teenage brains have for novelty, risk and immediate rewards. Their frontal lobes, the regions that synthesize and organize information, that consider the consequences of actions, and serve to inhibit impulsive behavior are not fully developed, nor will they be until the early to mid 20s. That, in a nutshell, is the teenage brain, designed to respond to the “siren song” of the world’s temptations.

That is all well and good for survival of the species as a whole, but how are we to handle these juvenile traits in a society where the rule of law maintains the social order and individuals are held responsible for what they do? Some of the “rewards” that are so compelling for teen brains are social plagues – drugs of abuse, gang affiliations, aggressive provocations.

What should we do in a case like Jimmy Moran’s, where an adolescent caused grievous harm to an innocent adult? In a series of cases between 2005 and 2012, the United States Supreme Court grappled with just these issues and came out with a new framework. Incorporating neuroscientific and behavioral evidence demonstrating that the adolescent brain typically lacks the impulse control, planning and risk avoidance capacities of the adult brain, it determined that capital punishment of juveniles is cruel and unusual, and therefore unconstitutional. Further, the Supreme Court said that if a juvenile is to be sentenced to life without the possibility of parole, this should be only for crimes of homicide and must determined on a case by case basis, necessitating individual assessments of the particular juvenile’s maturity.

What might be important to discuss at such a hearing on juvenile legal responsibility? The issues elegantly raised in Jimmy’s trial. The judge and the jury might learn about the vulnerabilities of all adolescent brains and then examine both the brain and behavior of the teen before the court. Most teenagers are behavioral risk takers, but were there any other circumstances, which heightened or ameliorated this risk?

Jimmy had deficits of attention, which made school extremely difficult, and a street life the path of less resistance. Further he had particular problems in processing information rapidly, and was inherently socially immature – both factors leading to his vulnerability of being manipulated and subject to peer pressure. He also had traumatic experiences at home, which made violence seem an acceptable solution to frustration and anger. Both mother and he were abused, and he developed post-traumatic stress disorder (PTSD), an anxiety condition that makes a child more prone to feel helpless and vulnerable. To compound matters, the situation at home – his attachment to an abused mother, and a longing for acceptance from a disabled father, resulted in an urgent but unrealistic plan to help provide financially for the family (remember, his frontal lobe is paving the way for impulsive behavior without regard for the consequence). His eventual depression and cocaine use compounded his difficulty with thoughtful, responsible decision-making.

Individuated sentencing hearings in place of mandatory minimum sentences can also be a two edged sword, as a judge might find that a particular teenager had ample capacity to resist certain temptations, but chose not to, a finding that might increase culpability. On the other hand, the judge does have an ability to take into account many mitigating forces, such as the ones we see in Jimmy Moran. Finally, even a teenager with a relatively more mature frontal lobe can become disinhibited by drug or alcohol use – the single greatest accelerant for irresponsibility in teens and adults.

If you use this model, you can both do justice in the setting of a terrible crime and see obvious points of intervention to prevent violence in the future. Importantly, each specific clinical problem of Jimmy’s may be helped by good, comprehensive treatment: attention difficulties, learning weaknesses, family problems (domestic violence and economic burdens), PTSD, depression and substance use.

By targeting violence prevention in and outside the home, by offering early treatment for psychiatric conditions and by implementing strategies for substance abuse prevention, we can take advantage of the inherent rehabilitation potential in these vulnerable teen brains before tragedy strikes.

Judith Edersheim, is Co-Director, MGH Center for Law, Brain & Behavior and Assistant Clinical Professor in Psychiatry, Harvard Medical School. For more information see:

Gene Beresin is: Director of the MGH Clay Center for Young Healthy Minds: Developing Resilience through Engagement, Awareness and Media (DREAM) and Professor of Psychiatry at Harvard Medical School. For more information see: Follow Gene and the Clay Center on Twitter here: @GeneBeresinMD and @MGHClayCenter.

Steve Schlozman, MD, is Co-Director of Medical Student Education in Psychiatry and Assistant Professor of Psychiatry at Harvard Medical School. He is Associate Director of the MGH Clay Center for Young Healthy Minds.