Abstract:

Activities on social network site can be classified into two main types: active use and passive use. Previous studies revealed that active use of social network site, such as self-presentation and self-disclosure, could enhance social capital, self-esteem and life satisfaction, as well as reduce loneliness. On the contrary, passive use of social network site could exert adverse effects on emotional well-being and life satisfaction, and might lead to depression. However, little is known about the effect of passive use of social network site on self-concept, in particular, effects on self-esteem and self-concept clarity. Passive use of social network site exposes individuals to a lot of positive information of others, which may result in upward social comparison. Upward social comparison in turn negatively impacts individuals’ self-esteem and self-concept clarity. But individuals are not equally influenced by upward social comparison. Optimism, as an important personality trait, may impact the way individuals process information of upward social comparison and thus alleviates the negative effects of upward social comparison. Therefore, the present study aimed to examine the mediating roles of upward social comparison in the effects of passive use of social network site on self-esteem and self-concept clarity. The study would also test whether the mediating effects of upward social comparison would be moderated by optimism. A sample of 1208 undergraduate students (mean age = 19.86; SD = 1.26) were recruited for the study to complete a battery of self-report questionnaires measuring their passive use of social network site, upward social comparison on social network site, self-esteem, self-concept clarity and optimism. All the measures showed good reliability and validity in the present study. Data were analyzed using SPSS 17.0 and SPSS macro PROCESS which was specifically developed for assessing the complex models including both mediators and moderators with the bias-corrected percentile Bootstrap method. The results were as followings: (1) After controlling for gender, grade and mean time of social network site use per day, passive use of social network site had no significant direct effect on self-esteem. But it could negatively predict self-esteem through the mediation of upward social comparison. (2) Passive use of social network site had significant effect on self-concept clarity, and could also negatively predict self-concept clarity through upward social comparison. (3) The mediating effects of upward social comparison in the association between passive use of social network site and self-esteem and between passive use of social network site and self-concept clarity were both moderated by optimism. The indirect effects were stronger for individuals with a low level of optimism. (4) For individuals with a high level of optimism, the direct effect of upward social comparison on self-esteem and the mediating effect of upward social comparison in the association between passive use of social network site and self-esteem were not statistically significant. But the direct effect of upward social comparison on self-concept clarity and the mediating effect of upward social comparison in the association between passive use of social network site and self-concept clarity were both significant. The present study highlights the mediating effect of upward social comparison and the moderating effect of optimism in the effect of passive use of social network site on self-esteem and self-concept clarity. It may contribute to a better understanding of the effects, mechanisms, and the conditions of passive use of social network site on self-esteem and self-concept clarity.

Key words: passive use of social network site, upward social comparison, self-esteem, self-concept clarity, optimism