| 【Abstract】 Background The middle school stage represents a crucial period for the development of borderline personality features. Both negative parenting styles and emotional regulation strategies are associated with the formation of borderline personality features (BPF). However, the moderating role of emotional regulation strategies between negative parenting styles and BPF among middle school students remains unclear. Objective To investigate the moderating influence of cognitive reappraisal and expressive suppression strategies on the association between negative parenting styles and borderline personality features among middle school students, and to offer a theoretical foundation for the early intervention of borderline personality features. Methods In October, 2023,5 965 middle school students from three middle schools in Nanning, Guangxi Zhuang Autonomous Region were selected by simple random sampling, and assessed by BPFS-C, EMBU and ERQ-CRV. Spearman correlation analysis was used to test the correlation between the scores of each scale, and PROCESS macro program was used to test the moderating effect of model 1. Results A total of 5 572 middle school students (93.41%) completed this study, and 1 388 middle school students (24.91%) were found with high borderline personality features. middle school students' BPFS-C scores were positively correlated with EMBU negative parenting styles score and ERQ-CRV expressive suppression score (r=0.367, 0.344, P<0.01), and negatively correlated with ERQ-CRV cognitive reappraisal score (r=-0.168, P<0.01). Cognitive reappraisal plays a negative regulatory role between negative parenting styles and borderline personality features (β=-0.072,95% CI:-0.104 – -0.041,P<0.01), while expressive suppression plays a positive regulatory role (β=0.076,95% CI:0.055 – 0.097,P<0.01). Conclusion Cognitive reappraisal strategy can cushion the negative influence of negative parenting styles on middle school students' borderline personality features, while expressive suppression may amplify the harm of parents' negative parenting style on middle school students' borderline personality features. |