chevron-down Created with Sketch Beta.
August 01, 2015

Understanding the Adolescent Brain and Legal Culpability

Morgan Tyler

The views expressed herein have not been approved by the House of Delegates or the Board of Governors of the American Bar Association, and accordingly, should not be construed as representing the policy of the American Bar Association.

Only 11 years old, Xavier McElrath-Bey joined a gang on the south side of Chicago. At age 13, Xavier was sentenced to 15 years in prison for a gang murder. He was released from jail at age 28 with a college degree and a desire to make a difference in the world. Xavier now advocates for youth rights and fair sentencing of juveniles for the Campaign for Fair Sentencing of Youth. Xavier has dedicated his life to preventing juveniles from traveling a similar path. 

Xavier joined an expert panel at the ABA webinar, “Rethinking Juvenile Justice: Adolescent Brain Science and Legal Culpability,” on June 10, 2015. Experts highlighted how juveniles’ brains differ from adults’ and how those differences should be weighed when deciding their legal culpability for committing crimes. 

Experts included: 

  • Jennifer Woolard, associate professor of psychology at Georgetown University and co-director of the graduate program’s Human Development and Public Policy track; 

  • Robert Kinscherff, senior administrator and director of the concentration in Forensic Psychology in the doctoral clinical psychology program at William James College; and

  • Marsha Levick, co-founder, deputy director and chief counsel of the Juvenile Law Center, America’s oldest public interest law firm for children.

How the Juvenile Brain Functions

While juveniles can be legally tried as adults, their brains are extremely different, said Kinscherff. One of the key differences between adult and adolescent brains, highlighted by Kinscherff, is the lack of prefrontal cortex development in young brains. The prefrontal cortex controls humans’ ability to:

  • delay and reflect (the lack of development limits the amount of time juveniles will think before they act);

  • take all options into account (juveniles are extremely impulsive); 

  • contemplate risks and consequences (sensation seeking is at an all-time high at mid-adolescence); 

  • have social intelligence (juveniles have difficulty being empathetic and are susceptible to peer pressure).  

Two other brain systems that are key for understanding the adolescent brain include the social-emotional system and the cognitive control system. 

The social-emotional system includes the limbic midbrain system and the orbital frontal areas of the frontal lobe. It develops faster than the cognitive control system. The social-emotional system controls the emotional state of the brain. With the rapid development of this system teens have:

  • increased need for a sense of rewards,
  • increased sensation seeking,
  • more reactive emotional responses to both positive and negative emotions,
  • increased attentiveness to social cues.

The cognitive control system includes the dorsolateral area of the frontal lobe. This system provides a check to the social-emotional system, but takes longer to develop. As the cognitive control system matures through adolescence it provides:

  • increased impulse control,
  • better emotional regulation,
  • more foresight and detection of options,
  • better planning and anticipation of outcomes,
  • greater resistance to stress and peer pressure.

With differences in development, the brain is essentially being given the “gas” of the social-emotional system without having mature “brakes” of the cognitive control system. This leads to these trends in the juvenile brain:

  • Impulsivity declines with age.

  • Sensation seeking declines with age.

  • Susceptibility to peer influence declines with age.

  • Time spent problem solving increases with age.

  • Gratification delays increase with age.

Applying Neuroscience to Juvenile Culpability

Woolard highlighted how adolescent defendants may have less criminal culpability than their adult counterparts based on the latest neuroscience. The legal process is confusing no matter the age of the defendant. When polled, the percentage of people who thought admitting to a crime when questioned by the police was the right response decreased from nearly 60% at age range 11-13 to less than 20% at age range 18-24. This data shows that a mere difference of seven years has a huge effect on the legal responses of a defendant. Woolard outlined three ways that including more information about adolescent brain development might affect legal practice when representing juveniles charged with committing crimes:

  • Change assumptions about juveniles; they are different than adults and their behavior needs to be judged in the context of their development.

  • Offer new information and findings to be considered in forensic evaluations, social histories, and presentence reports. 

  • Aid in explaining interactions and relationships between adolescents and other key players in the court system, probation offices, judges, etc.  in order to help the defendant understand the legal process. 

Court Application 

Levick described four cases in which the United States Supreme Court has considered neuroscience research when sentencing youth who commit crimes: 

  • Roper v. Simmons, 543 U.S. 551, decided in 2005, dealt with a 17-year-old defendant sentenced to the death penalty in Missouri. The Court ruled that imposing the death penalty on juveniles who commit crimes when they are under age 18 violates the Eighth Amendment’s prohibition against cruel and unusual punishment. The decision effectively banned the juvenile death penalty nationwide. The Court considered differences between juveniles and adults, finding that juveniles have less impulse control, increased susceptibility to peer influence, and lack of good reasoning making them less culpable than adults. 

  • Graham v. Florida, 560 U.S. 48, came before the Court in 2010. Sixteen-year-old Graham was convicted of attempted armed robbery and armed burglary. After his release, he violated his probation and was then sentenced to life without parole. The Court ruled that sentencing Graham to life without parole for committing a nonhomicide offense constituted cruel and unusual punishment for juveniles. The science supporting this ruling builds off Roper, noting huge fundamental brain differences between adults and children. Juveniles’ actions are less likely to demonstrate negative moral character, unlike adults, creating less possibility of repeated offenses and better rehabilitation outcomes.

  • In 2012, the Court ruled in Miller v. Alabama, 132 S.Ct. 2455, that juveniles cannot be subjected to mandatory life without parole. Fifteen-year-old Miller committed a homicide and was given a life sentence without parole. The Court decided sentencing should be conducted on a case-by-case basis, taking factors such as the juvenile’s developmental stage and education into account. Three scientific facts supported the Court’s reasoning: children lack maturity, which can be seen in their increased impulsivity and risk-taking; children are more vulnerable to negative influences from their environment or peers; and children’s moral character is not fully developed, proving that their actions are not necessarily “evidence of irrebuttable depravity.” Roper 543 U.S., 569.  
  • In J.D.B v. North Carolina, 131 S.Ct. 2394, decided in 2011, 13-year-old J.D.B was questioned by police and school administrators in his middle school about recent robberies. He was not read his Miranda rights or told that he was free to leave and eventually confessed to the robberies. The Court ruled that age is relevant in determining police custody for Miranda purposes and that children have a different perception of the legal system. Because they are easily influenced by their environments and peers, children do not understand the legal system and police custody in the same way that an adult would. 

These rulings are changing the landscape for juvenile defendants throughout the country. Greater awareness of the differences in adolescent brain development and how they affect juveniles' behaviors is increasingly being recognized by the Court, helping to ensure children are adjudicated more fairly.


The convergence of adolescent brain science and the legal system is essential for fair and accurate trials and sentencing of juveniles. Juveniles’ developmental context plays a huge role in their legal culpability and should be considered in court. The recent Supreme Court rulings have paved the way for using brain science in court in juvenile cases. 

Morgan Tyler is student at the College of William & Mary and is participating in the D.C. Summer Leadership & Community Engagement Institute as an intern at the ABA Center on Children and the Law.