The combined effects of relationships on smartphone dependence and the age differences

Previous studies have proved the importance of relationships for students' smartphone use and addiction, but we knew little about the combined effects of relationships. In 7920 children (M-age = 10.29, SD = 0.56) and 14,354 adolescents (M-age = 14.13, SD = 0.50), we explored the combined effects of parent-child relationship (PCR) and peer relationship (PER) on smartphone use and addiction through a comprehensive analysis method-response surface analysis (RSA). Through RSA, we could provide the simultaneous and nuanced assessment of the combined effects in one model. Results revealed that when PCR and PER matched, the combined effects conformed to additive model, which meant good relationships protect students. When relationships mismatched, for children, the combined effect conformed to compensation mode, which meant even just one good relationship could protect students; but for adolescents, their good PER played interferential roles, increasing the risk of smartphone addiction and use. The results helped to intervene students' smartphone use in more practical ways.