Abstract
In the current information era, even preschool children are unable to withstand the "digital flood". However, excessive exposure to electronic screens not only negatively impacts various aspects of children's health and adaptation, but also harms family relationships. Based on family systems theory, social-cognitive learning theory, and attachment theory, this study examines the relationships between co-parenting and preschoolers' problematic media use, as well as the underlying mechanism-the mediating role of parental phubbing and the moderating effect of secure attachment. A sample of 610 parents of preschoolers from three kindergartens in central China completed validated scales, including the Co-Parenting Scale, Parental Phubbing Scale, Children's Electronic Media Use Questionnaire, and Secure Attachment Dimension of the Waters Attachment Q-sort. A moderated mediation model was tested using the PROCESS macro with bootstrap procedures. The results showed that, after controlling for the subjective family socioeconomic status and parental education level, (1) co-parenting was negatively associated with preschoolers' problematic media use; (2) parental phubbing significantly mediated the relationship between co-parenting and preschoolers' problematic media use; (3) secure attachment significantly moderated both the direct relation between co-parenting and the preschoolers' problematic media use and the mediating effect of parental phubbing (the relation between parental phubbing and children's problematic media use); furthermore, both of these effects were more pronounced in children with lower levels of secure attachment. These findings extend family systems and attachment theories by elucidating mechanisms underlying early media behaviors. Practically, interventions should promote collaborative co-parenting and reduce parental phubbing to mitigate children's problematic media use, while fostering secure attachment to buffer digital risks.