Juveniles' right to be competent to stand trial has been increasingly recognized since In re Gault (1967) granted juveniles essential due process rights. One formulation of competence proposes two facets: competence to assist counsel (e.g., understanding the roles of legal actors, the adversarial system,) and decisional competence (Bonnie, 1992). The first goal of this project was to investigate the psychometric properties and relevant correlates of one instrument to assess competence to assist counsel, the Competence Assessment for Standing Trial for Defendants with Mental Retardation (CAST-MR; this study used only the first two scales). Results indicated acceptable internal consistency, although concerns were raised regarding the appropriateness of some items. Scores were related to age and intelligence, as in prior research. No relationship was found with most mental health scale scores, prior legal system involvement, contact with defense counsel, or learning problems. The second goal of the study centered on decisional competence and the role of immaturity; specifically whether age is associated with immature judgment (assessed using the Judgment in Legal Contexts instrument) and if immature judgment predicts decisions made about one's own case. The current study found few significant relationships between age or intelligence and variables coded from the JILC (including authority compliance, risk recognition, risk appraisal, future recognition, resistance to peer influence). Additionally, age and the perceived strength of evidence were not predictive of individuals' decisions to confess, to fully disclose to defense counsel, or to accept a plea bargain. Juveniles who had confessed scored higher on future recognition, those who fully disclosed to their attorney scored lower on authority compliance, and those who would accept a plea bargain scored higher on risk recognition and appraisal. While the results were modest, they suggest that immature performance on a judgment measure may predict individuals' legal decision-making. If a juvenile fails to appreciate the potential consequences of legal decisions, his or her decisional competence may be questioned. Generally, immaturity may need to be recognized as a basis for findings of incompetence if performance on relevant skills is shown to improve with age and immature performance is shown to interfere with competency.

As the courts have evolved over the past 30 years towards increasingly punitive sanctions for youthful offenders, the fundamental protections afforded to adult defendants have become increasingly relevant for youthful offenders. Among these protections, the right of juveniles to be competent to stand trial has gained nearly universal recognition throughout this country’s courts. Congruent with theory and previous research, we hypothesized that age, intellectual ability, psychiatric symptomatology, and maturity would all be directly related to adolescents’ competence. It was also anticipated that adolescents in the detention sample would evidence lower maturity and competency-related abilities compared to the community sample. Expanding on previous research that has consistently documented an association between age and competence, we hypothesized that psychosocial maturity would partially mediate this relationship. Further, we hypothesized that psychosocial maturity would moderate the direct relations between intellectual ability, psychiatric symptomatology, and competence. In order to test these hypotheses, we utilized a secondary sample from the MacArthur Adjudicative Competence Study that included 927 male and female adolescents ages 11- to 17-years-old recruited from 11 juvenile detention facilities and their surrounding communities. Results demonstrated that age, intellectual ability, and maturity were each directly positively related to competence, and psychiatric symptomatology was negatively related to competence. Further, results provided some support for the hypothesis that maturity partially explains the relationship between age and competence. While the relationship between psychiatric symptomatology and competence did not vary across high and low levels of maturity, results supported the hypothesis that the relationship between intellectual ability and competence varies across high and low levels of psychosocial maturity. Findings suggest that intellectual ability plays an essential role in juveniles’ adjudicative competence and can serve as a protective factor against some aspects of immaturity. Given these findings, it is suggested that youth with deficient intellectual abilities facing the possibility of transfer be automatically referred for evaluations of adjudicative competence. Further, findings suggest that maturity appears to warrant further attention from researchers and clinicians involved in evaluating juveniles’ adjudicative competence. Results are discussed in terms of the legal and clinical implications of developmental immaturity on the prosecution of youthful offenders.