Attachment security and parental sensitivity during infancy: Associations with friendship quality and false-belief understanding at age 4

The current study investigated how attachment security and parental sensitivity during infancy were related to children's understanding of false belief and friendship quality during the preschool period (N = 30). At age 1, parent-infant attachment was assessed in the Strange Situation, and a 3-point security score based on the attachment subcategories was utilized. Also, at this time point, parental sensitivity was observed during two semi-structured interactive sessions. At age 4, child-friend interaction was observed during two laboratory play sessions, and understanding of false belief was assessed during child interviews. Correlational analyses revealed that greater maternal sensitivity during infancy was related to more positive and less negative child-friend interaction at age 4. Although neither mother-infant nor father-infant attachment security made a unique contribution to friendship quality, a significant interaction indicated that mother-infant attachment security was related to friendship quality, but only when father-infant attachment security was high. Moreover, children who experienced greater attachment security and greater parental sensitivity at age 1 were more likely to pass false belief tasks at age 4. Finally, children's false-belief understanding partially mediated the association between a composite of family-infant relationship quality and friendship quality during the preschool period.