Long-term developmental trajectories of callous-unemotional traits inform daily emotional reactivity to stress during the transition from late adolescence to young adulthood

Abstract Callous-unemotional (CU) traits are linked with various psychosocial maladjustments. Scant research has investigated its developmental pattern during the transition from late adolescence to young adulthood, and whether the pattern may function as a mechanism against daily stressors in stressful contexts. This study adopted a multi-timescale approach to elucidate how long-term developmental trajectories of CU traits relate to both socioemotional maladjustment and daily emotion dynamics during the transition period. A three-wave longitudinal study ( N = 313; M age = 18 years, 72% female, 30% White) with two 30-day daily diary bursts embedded over three years was conducted. Latent growth curve modeling revealed a modest group-level increase in CU traits. Higher initial levels and faster increase in CU traits were associated with higher depressive symptoms and peer problems and lower empathy and peer attachment in wave 3. Multilevel modeling showed that individuals with faster growth in CU traits displayed lower daily emotional problems, blunted reactivity to stress, and reduced stress-unrelated emotional fluctuations; these associations persisted over two-and-a-half years. These findings suggest that the developmental growth of CU traits may buffer daily stress reactivity in the short-term but could be maladaptive in the long-term.