Serial mediation pathways linking attachment security to loneliness: the role of self-disclosure quality and perceived social support among college students

Background: Loneliness among college students has reached epidemic proportions, yet the specific behavioral and environmental mechanisms through which attachment security protects against loneliness remain unclear. While previous research has focused on how attachment insecurity contributes to loneliness, less attention has been paid to understanding the protective pathways of attachment security. This study examined a serial mediation model in which self-disclosure quality and perceived social support sequentially mediate the attachment security-loneliness relationship. Methods: A cross-sectional survey of 1,098 Chinese college students (M_age = 20.15, SD = 1.28; 82.9% female) assessed attachment security (closeness dimension), self-disclosure quality (depth and honesty composite), perceived social support, and loneliness using validated instruments. Serial mediation analysis was conducted using PROCESS Model 6 with bootstrap confidence intervals. Results: The model explained 43.2% of loneliness variance. Three significant indirect pathways emerged: perceived social support alone (B = -0.433, 69.5% of total indirect effect), complete serial mediation through self-disclosure quality and perceived social support (B = -0.110, 16.9%), and self-disclosure quality alone (B = -0.084, 13.6%). All hypothesized relationships were supported, with perceived social support serving as the dominant protective mechanism. Conclusion: Perceived social support represents the primary pathway linking attachment security to reduced loneliness, while behavioral mechanisms through self-disclosure quality provide secondary protection. These findings advance understanding of attachment security's protective mechanisms and suggest that interventions should prioritize enhancing students' capacity to recognize and utilize available social resources, with supplementary focus on developing high-quality disclosure behaviors.