Low social affiliation predicts increases in callous-unemotional behaviors in early childhood

Background Callous-unemotional (CU) behaviors predict risk for aggression and rule-breaking. Low social affiliation (i.e. reduced motivation for and enjoyment of social closeness) is hypothesized to be a phenotypic marker for CU behaviors in early childhood. However, studies need to establish observational methods to objectively assess social affiliation as well as to establish parenting practices that can buffer pathways from low social affiliation to CU behaviors. Methods Using data from a longitudinal twin study of 628 children (age 2, 47% females; age 3, 44.9% females), we examined reciprocal associations between observed social affiliation, CU behaviors, and oppositional-defiant behaviors. We tested whether positive parenting moderated associations over time. Results We established that an observed measure of social affiliation derived from the Bayley's Behavior Rating Scale and Infant Behavior Record showed high inter-rater reliability and expected convergence with parent-reported temperament measures. Lower social affiliation at age 2 uniquely predicted CU behaviors, but not oppositional-defiant behaviors, at age 3. Finally, low social affiliation at age 2 predicted CU behaviors at age 3 specifically among children who experienced low, but not high, levels of parental positivity. Conclusions An objective rating scale that is already widely used in pediatric settings reliably indexes low social affiliation and risk for CU behaviors. The dynamic interplay between parenting and low child social affiliation represents an important future target for novel individual- and dyadic-targeted treatments to reduce risk for CU behaviors.