Parental intelligence and preschoolers' social competence: the mediating role of parental attachment behavior and the moderating effect of parent gender—A multi-informant study

Background Deficits in preschoolers' social competence—encompassing emotional understanding, peer cooperation, and conflict resolution—pose significant risks for later school adjustment and interpersonal relationships. Parental intelligence is a core cognitive parenting capacity, but the mechanisms linking it to child social outcomes remain underexplored. Most prior research has focused on maternal parenting, neglecting the synergistic effects of both parents' co-participation, and no study has systematically examined the role of parental attachment behavior as a mediator. Grounded in family systems theory and attachment theory, this study investigated whether parental attachment behavior mediates the relationship between parental intelligence and preschoolers' social competence, and whether parent gender moderates this mediation pathway. Methods Using a multi-informant design, data were collected from 763 preschoolers (aged 3–6 years) and their parents recruited from six kindergartens in Shandong Province, China. Parents self-reported parental intelligence (Parental Intelligence Scales) and attachment behavior (Maternal Attachment Inventory). Classroom teachers rated children's social competence (Iowa Social Competence Scale). Mediation and moderated mediation were tested using PROCESS Models 4 and 7. Results Parental intelligence was positively correlated with preschoolers' social competence ( r = 0.605). Mothers scored significantly higher on attachment behavior than fathers ( p = 0.005, Cohen's d = 0.24), but no gender difference emerged in parental intelligence. Parental attachment behavior partially mediated the association (indirect effect = 0.151, 95% CI [0.113, 0.189]), accounting for 39.4% of the total effect. Parent gender did not significantly moderate the mediated pathway (index of moderated mediation = 0.019, 95% CI [−0.008, 0.049]), indicating that the indirect effect was significant for both fathers and mothers—revealing cross-gender stability. Conclusions Parental attachment behavior serves as a crucial mechanism translating parental intelligence into children's social competence, and this pathway operates similarly for mothers and fathers. The non-significant moderating effect of parent gender empirically challenges traditional views that overemphasize parental role differences and provides novel evidence for co-parenting theory. Practically, family education interventions should simultaneously enhance both cognitive parenting capacity (parental intelligence) and affective attachment behaviors, engaging both parents equally.