Relationships among Problematic Smartphone Use, Mathematics Achievement, Teacher–Student Relationships, and Subjective Well-Being: Results from a Large-Scale Survey in China

This study examined the mediating role of mathematics performance and the moderating role of teacher–student relationships on the effects of problematic smartphone use on students’ subjective well-being. Through probability proportionate to size sampling (PPS), a total of 20,321 fourth graders from a city in central China were invited to complete a paper-based mathematics achievement test and an online questionnaire survey, including demographic information, problematic smartphone use, subjective well-being, and teacher–student relationship scales. The results showed that: after controlling for SES and gender, (1) problematic smartphone use had a direct and negative effect on students’ subjective well-being; (2) mathematics performance partially mediated the effects of problematic smartphone use on students’ subjective well-being; (3) teacher–student relationships moderated the effects of problematic smartphone use on mathematics performance/students’ subjective well-being; (4) with the increase in problematic smartphone use, high teacher–student relationships produced a lower rate of the positive moderating effect than low teacher–student relationships. The implications of this study and suggestions for future research are discussed.