Abstract

Non-suicidal self-injury (NSSI) is defined as the deliberate harm of one’s own body tissue without any intent to die. Utilizing online NSSI disclosure on social media, this thesis offers new insight into the emotional and interpersonal functions of NSSI. Using 462,287 social media posts from 398 female users who disclosed NSSI on Weibo, Study 1 found a decrease in positive emotion following NSSI compared to the pre-NSSI period. To further explore the reasons behind, Study 2 utilized self-report data from 254 female participants with NSSI history, finding that individuals were reluctant to disclose positive emotions due to the concerns of social desirability and the perceived emotional support from others. Furthermore, the cross-validation of NSSI emotional experience from self-report data showed that while positive emotions were experienced immediately after NSSI, they faded away over the following days. These findings underscore the critical roles of both emotional and interpersonal motivation in NSSI, and highlight online disclosure as a valuable channel for future research in NSSI.