Challenging the golden mean: Testing the inverted U‐shaped relationship between trait self‐control and subjective well‐being among Chinese adolescents

Abstract Self‐control (SC) is a robust predictor of subjective well‐being (SWB), and a positive linear relationship between them is often taken as the default assumption. However, some perspectives suggest that excessive SC may diminish SWB, implying an inverted U‐shaped relationship. This study examined this inverted U‐shaped hypothesis among Chinese adolescents, who are raised in a culture emphasizing moderation. We analyzed five samples (total N = 25,936), including four cross‐sectional samples, two of which were nationally representative, and a three‐wave longitudinal sample collected over two years. Participants ranged from middle school to university students, with SC assessed via self‐ and parent‐report, and SWB through multiple indicators including positive and negative affect, life satisfaction, and one‐item happiness assessment. Quadratic regression analyses and Simonsohn's two‐lines test found no inverted U‐shaped relationship between SC and SWB in five samples. Instead, SC consistently correlated positively with SWB across samples, regardless of measurement methods or whether data were cross‐sectional or longitudinal. These findings reinforce the notion that higher SC contributes to greater SWB, with no indication of an inverted U‐shape in Chinese culture. Encouraging the development of SC in adolescents might be a beneficial approach to enhancing long‐term well‐being, without concerns about unintended negative consequences.