Kinship Support Differentially Predicts Problematic Smartphone Use in Left-behind Children Compared to Non-left-behind Children: A Longitudinal Study

Currently, severe problematic smartphone use among left-behind children in China is a prevalent issue. However, there is still relatively little research focusing on left-behind children's problematic smartphone use. Left-behind children refer to children aged 6-16 who are left behind in their rural hometowns due to at least one of their parents working outside of the hometown. Based on the family systems theory, this study aims to investigate the predictive associations between different types of kinship support (parental support, grandparental support, and other relatives' support) and problematic smartphone use among left-behind children. A total of 415 children participated in our survey, undergoing three longitudinal tests (Mage= 12.95, SD = 0.92, 286 left-behind children, 129 non-left-behind children). The results indicated that, compared to non-left-behind children, parental support had a more stable negative delayed effect (delayed effects mean stable predictive effects across time) on problematic smartphone use of left-behind children. Moreover, other relatives' support had a marginally significant negative prediction on problematic smartphone use in left-behind children. Conversely, grandparental support had a positive delayed effect on problematic smartphone use of left-behind children, unlike the negative delayed effect of grandparental support on non-left-behind children's problematic smartphone use. These findings highlight the differential effects of various kinship support systems on problematic smartphone use among left-behind children, providing new insights for intervention strategies based on the family systems theory.