Juvenile psychopathy and its relation to immaturity: Maturational growth mediates associations between adolescent and adult psychopathy scores

Psychopathic traits tend to decline from adolescence to adulthood, which could be attributed to aging out of inherently "juvenile" characteristics that resemble psychopathy (e.g., parasitic lifestyle, impulsivity, lying, reward sensitivity). Simultaneously, Maturity of Judgment (MoJ) improves over this period, with components of such (e.g., emotional maturity, consideration of others, future outlook) resembling psychopathy-related deficits. This study assessed the co-development of psychopathy and MoJ through a parallel process model, and in a separate mediation model, tested whether advances in MoJ partially explained variance between adolescent and young adult psychopathy scores. By examining data from the Pathways to Desistance, a longitudinal study of 1170 justice-involved males (Mage = 16, range = 14-17) who were interviewed across 11 waves spanning 7 years following a serious offense, we found the growth of psychopathy (shown to decline across the study) was significantly related to the growth of MoJ (increased across the study). We found significant indirect pathways linking adolescent psychopathic traits to young adult psychopathic traits 7 years later (i.e., Callous-Unemotional, Grandiose-Manipulative, Impulsive-Irresponsible) through the MoJ trajectory (p < .05), such that gains in maturity explained variance in psychopathic traits from adolescence to young adulthood. Our results suggest that developmental changes in maturity may contribute to individual differences in the continuity and expression of psychopathic traits across adolescence and young adulthood. Findings have implications for interpretability of juvenile assessments, treatment opportunity, and legal decision-making considerations.