This study tested the hypothesis that social engagement (SE) with peers is a fundamental aspect of social competence during early childhood. Relations between SE and a set of previously validated social competence indicators, as well as additional variables derived from observation and sociometric interviews were assessed using both variable-centered and person-centered approaches (N = 1453, 696 girls) in 4 samples (3 U.S.A., 1 Portuguese). Directly observed SE was positively associated with broad-band measures of socially competent behavior, peer acceptance, being a target of peers' attention, and also with broad-band personality dimensions. Using individual Q-items significantly associated with SE in 3 of our 4 samples, a hierarchical cluster analysis yielded a 5-cluster solution that grouped cases efficiently. Tests on relations between cluster membership and the set of social competence and other variables revealed significant main effects of cluster membership in the full sample and within each individual sample, separately. With the exception of tests for peer negative preference, children in the lowest SE cluster also had significantly lower overall social competence, personality functioning scores than did children in higher SE clusters. (author abstract)