The U.S. high court has made it official: 16 and 17 year olds are not as mature as adults are. In a 5-4 decision announced today, the Supreme Court ruled that adolescents who commit capital crimes will not be subject to the death penalty. Scientists and lawyers believe growing research into teen brain development and adolescent behavior may have played a role in the outcome.
Last year, the U.S. Supreme Court reviewed a death penalty case in which the defendant was 17 at the time of his crime. At issue was whether execution was "cruel and unusual punishment" for 16 and 17 year olds. Eight medical organizations, led by the American Society for Adolescent Psychiatry (ASAP), filed a friend-of-the-court brief in support of the defendant, Christopher Simmons. The groups cited numerous neuroscientific and behavioral studies suggesting that brains continue to develop well into the mid-20s, and that the last region to develop is the prefrontal cortex, which prevents people from making rash, impulsive decisions (Science, 30 July 2004, p. 596). "These developmental differences make them less culpable and therefore less deserving of the ultimate punishment," argues law professor Steven Drizin of Northwestern University in Chicago.
Officially, the justices concluded that "changing standards of decency" in the U.S. and around the world support the idea that teens are not as culpable as adults when they make bad decisions. They write that teens "lack maturity and have an underdeveloped sense of responsibility," and most states already prohibit teenagers from voting, serving jury duty, and marrying. The court also cites evidence that adolescents are more susceptible to peer pressure.
Although the justices didn't note specific brain development studies in their written decision, advocates believe science influenced the ruling. "Clearly the scientific evidence created a framework in which the court could distinguish between adolescents and adults," says Drizin.
"It's obviously very good news," says physician David Fassler, spokesperson for the American Psychiatric Association and the American Academy of Child and Adolescent Psychiatry (AACAP). "The ruling is consistent with all the major medical organizations." According to the AACAP, the decision means that 73 death row offenders in 12 states will have their sentences commuted.
Roper vs. Simmons Supreme Court decision
Teenage Brain: A work in progress from the NIH
Juvenile Justice Committee at American Bar Association: