Extensive research has shown that callous–unemotional (CU) traits in middle-childhood and adolescence are markers for a particularly severe and chronic pattern of antisocial behavior (Frick et al. in Psychol Bull 140:1–57,
2014). Comparatively little, however, is known about the relationship between CU traits and antisocial behavior in early childhood. A meta-analysis of
k = 10 studies comprising n = 5731 participants was conducted to examine the relationship between CU traits and conduct problem severity prior to 5 years of age. Overall, a significant positive relationship was found between CU traits and conduct problem severity, in the order of large effect size (
r = .39,
p < .001). Moderator analyses revealed that this relationship differed based on use of same versus different informant across measures, but was consistent across sex and sample type (at-risk/clinic referred or community). This supports the view that CU traits represent a potentially informative focus for clinical assessment in early childhood.