Supreme Court relies on psychological research to prohibit juvenile sentences of life without parole in homicide cases

Behavioral science evidence concludes that youth differ in meaningful ways from adults, resulting in less-severe sentences for juvenile offenders in court

The U.S. Supreme Court’s recent decision (PDF, 377KB) in Miller v. Alabama (567 U.S. ____ ) extends the Court’s consideration of youth sentencing to further limit the sanctions for adolescents. In Miller, the Court held that laws requiring mandatory sentences of life in prison without possibility of parole are unconstitutional when applied to homicide defendants 14 years and younger. In earlier cases, the Court found that the Eighth Amendment prohibits capital punishment for children (Roper v. Simmons, 543 U.S. 551) and that life-without-parole sentences for juveniles are prohibited in nonhomicide convictions (Graham v. Florida, 560 U. S. ____ ). 

In all three cases, the Court relied on behavioral science evidence to conclude that youth differ in meaningful ways from adults. Drawing from amicus curiae briefs submitted by APA, the Court discussed adolescents’ “lack of maturity,” “underdeveloped sense of responsibility,” “impulsivity,” and “vulnerability to outside pressures” as key developmental differences between youth and adults (Roper, p. 569). In Miller, the Court reasoned that mandatory sentencing laws prevent the court from considering the age of the defendant and the proportionality of the sentence for punishing him or her. In perhaps their strongest statement to date acknowledging the developmental status of juveniles, the Court stated: “...imposition of a State’s most severe penalties on juvenile offenders cannot proceed as though they were not children” (Miller, p. 3).

The Children, Youth and Families Office provide more information about APA’s work supporting children, youth and families.