The association of Big-Five personality with co-rumination and its trade-off effect in Chinese adolescents: a cross-sectional study.

Introduction: Co-rumination, the excessive discussion of negative events with peers, exhibits a trade-off effect: it enhances friendship quality while simultaneously increasing the risk of internalizing problems in adolescents. Previous research has demonstrated group differences in this trade-off effect. Building on prior findings, this study explores the relationship between the Big Five personality traits and co-rumination among Chinese adolescents through three analytical components, aiming to identify at-risk groups for co-rumination using personality traits. Methods: This cross-sectional study collected 765 valid self-reported responses. Measurement invariance of the Chinese version of the co-rumination questionnaire was examined, and latent variable structural equation models were constructed for each of the three research objectives to investigate the relationship between the Big Five traits and co-rumination. Results: First, measurement invariance of the co-rumination questionnaire was assessed, revealing scalar invariance across gender and partial scalar invariance across age groups. Subsequent analyses examined the relationship between the Big Five traits and co-rumination. The first part showed that extraversion, neuroticism, and openness positively predicted co-rumination, while neuroticism explained gender differences in co-rumination. The second part confirmed the moderated trade-off effect of co-rumination; after controlling for the Big Five traits, the risk pathway of co-rumination became more robust, with gender differences observed in this pathway. The third part revealed distinct moderating effects of neuroticism, agreeableness, extraversion, and conscientiousness on the risk pathway. Discussion: Given the measurement invariance results, the Chinese co-rumination questionnaire should be used more cautiously in studies involving multiple age groups. Structural equation modeling indicated that neuroticism serves as a strong indicator for identifying at-risk groups, as individuals with high neuroticism are more susceptible to risks associated with co-rumination. High conscientiousness and agreeableness were found to buffer against co-rumination-related depression and anxiety, respectively. The roles of openness and extraversion in relation to co-rumination appear more complex. Further research is needed to validate these findings.