Legal issue
Juvenile Sentencing & the Eighth Amendment
Proportionality limits on the harshest sentences (death, life without parole) for offenses committed as a juvenile.
Claims under this issue
Adolescent personality and character are still forming and are not reliable indicators of fixed adult character; most adolescents who engage in antisocial behavior, including serious offending, desist as they mature, so adolescent conduct is a poor predictor of irretrievable depravity.
Evidence strength: HighScientific consensus: Established· adolescent personality development / desistanceAdolescents weigh risks and rewards differently from adults: a reward-sensitive socio-emotional system matures earlier than the cognitive-control system, producing heightened reward-seeking, a weaker orientation to the future, and steeper discounting of delayed consequences during adolescence.
Evidence strength: HighScientific consensus: Established· adolescent risk/reward processingAdolescents have a diminished capacity for self-regulation and impulse control relative to adults; the neural systems supporting cognitive control and behavioral inhibition mature gradually across adolescence and do not reach adult levels until the late teens to early twenties.
Evidence strength: HighScientific consensus: Established· adolescent self-regulation / impulse controlThe structural maturation of the human brain -- including cortical gray-matter thinning and continued development of white-matter connectivity in regions that support cognitive control -- continues throughout adolescence and into the early-to-mid twenties, later than the maturation of many other organ systems.
Evidence strength: HighScientific consensus: Established· adolescent structural neurodevelopmentStructured, developmentally-appropriate interventions can, on average, reduce reoffending among juveniles; as a group, adolescents are responsive to rehabilitation -- though effects are modest and depend strongly on the type of program, the targeting of higher-risk youth, and the quality of implementation.
Evidence strength: ModerateScientific consensus: Established· juvenile rehabilitation / intervention effectiveness