Claims

A substantial proportion of juveniles, especially those age 15 and younger, have impairments in adjudicative competence -- the capacities to understand legal proceedings, reason about legal decisions, and assist counsel -- at rates comparable to adults found incompetent to stand trial; developmental immaturity itself, apart from mental illness, can diminish trial competence.

Juveniles, especially those age 15 and younger, frequently do not adequately comprehend or appreciate the Miranda warnings they waive: as a group they understand the words of the warnings, and the function and significance of the rights to silence and counsel, less well than adults -- raising doubt about whether a juvenile's waiver is knowing and intelligent.

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.

Adolescents 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.

Adolescents 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.

The 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.

Adolescents are more susceptible than adults to peer influence and to external pressure or coercion, with susceptibility greatest in mid-adolescence; the mere presence of peers measurably increases adolescents' risk-taking and shifts their decisions toward immediate rewards.

At the population level, childhood adversity -- adverse childhood experiences (ACEs) such as abuse, neglect, and household dysfunction, and a harmful family or home environment -- is associated with an elevated risk of adolescent antisocial and delinquent conduct, in a graded, dose-response pattern (more cumulative adversity, higher average risk).

A child's age objectively affects how they experience police questioning: minors are more susceptible than adults to perceived pressure and authority, are more suggestible, and are at greater risk of falsely confessing, so age is materially relevant to whether a reasonable person would feel free to leave or to remain silent.

Structured, 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.

Juveniles are over-represented among proven false confessions, and adolescents are at elevated risk of false confession relative to adults -- a dispositional vulnerability (immaturity of judgment, suggestibility, and compliance with authority) that interacts with situational interrogation pressure. The claim concerns the composition of known and proven cases and comparative risk, not a known absolute rate among all juvenile confessions.