Despite the acknowledged significance of callous-unemotional (CU) traits in developmental psychopathology, few studies have examined their early antecedents in typically developing children, in long-term longitudinal designs, using observational measures. In 102 community mothers, fathers, and children (N = 51 girls), we examined main and interactive effects of children's fearless temperament and low concern about transgressions from toddler to early school age as predictors of CU traits in middle childhood and early preadolescence. In laboratory paradigms, we observed children's concern about breaking valuable objects (twice at each age of 2, 3, 4.5, 5.5, and 6.5 years) and about hurting the parent (twice at each age of 2, 3, and 4.5 years). We observed fearless temperament during scripted exposure to novel and mildly threatening objects and events (twice at each age of 2, 3, 4.5, and 5.5 years). Mothers and fathers rated children's CU traits and externalizing behavior problems at ages 8, 10, and 12. Children's low concern about both types of transgressions predicted CU traits, but those effects were qualified by the expected interactions with fearless temperament: Among relatively fearless children, those who were unconcerned about transgressions were at the highest risk for CU traits, even after controlling for the strong overlap between CU traits and externalizing problems. For fearful children, variation in concern about transgressions was unrelated to CU traits. Those interactions were not significant in the prediction of externalizing problems. The study highlights a potentially unique etiology of CU traits in early development.
Keywords: Callous-unemotional traits; Concern about transgressions; Fearless temperament.