Abstract: With the sweeping progress of technology and environment, people will automatically check their mobile software and generate corresponding information behaviors in the mobile social environment. Users’ perception of Fear of Missing Out (FoMO) in the mobile social media environment has gradually become a prevalent phenomenon. This phenomenon has been defined as “a pervasive apprehension that others might be having rewarding experiences from which one is absent”. Prior research have shown that FOMO may be linked to general unhappiness, negative mood, and depressed feelings. More attention has been paid to explore the mechanism of FOMO. FOMO in social media environment is associated with the use of social networking sites that divided into active use and passive use. Passive Use of Social Networking Sites(PUSNS) takes a long time for individuals and more likely to arouse such negative emotions as anxiety. Research has shown that PUSNS is an important factor influencing FOMO, but few studies have demonstrated the influence mechanism. According to the Social Selection Hypothesis, most of the individual's emotional problems stem from maladaptive cognitive biases such as perceived stress. Perceived stress produced by PUSNS is an important cause of FOMO. In addition, researchers point out that there are complex interactions between influence factors of FOMO. This study hypothesized that optimism as a protective factor for individual development can alleviate the negative effect caused by FOMO. In addition, it has been found that there is gender differences of optimism’s moderating effect in other variables. This study also investigated the gender differences of optimism’s moderating effect in the relationship between PUSNS and perceived stress or FOMO. The purpose of this study is to explore the influence mechanism of PUSNS on FOMO. By convenient sampling, totally 443 college students (186 boys and 257 girls) who have experience in using social networking sites were recruited to participate in this study. They were tested with the scale for the passive use of social networking sites, the perceived stress, the optimism, the fear of missing out. All the measures showed good reliability and validity in the present study. The results indicated that: (1) passive use of social networking sites has a positive direct effect on FOMO. (2) The positive association between passive use of social networking sites and FOMO was mediated by perceived stress, and there is gender difference in this indirect effect. The indirect effect was stronger for girls than boys. (3) optimism moderated the effect of passive use of social networking sites toFOMO. To be more specific, the relationship between passive use of social networking sites and FOMO was much stronger for college students with low optimism relative to those with high optimism. In addition, only in the male group, the moderating effect of optimism is significant. These findings had significant theoretical and applicable values and would contribute to reducing people’s FOMO. Firstly, it is beneficial to reduce passive use of social networking sites. Secondly, it is important to help college students to improve the level of optimism. Last, the interventions for college students’ fear of missing out should pay attention to the combined influence of those factors.

Key words: passive use of social networking sites, fear of missing out, perceived stress, optimism

摘要： 本研究为考察被动性社交网站使用对移动社交媒体环境下大学生错失焦虑症的预测，以及压力知觉的中介作用、乐观的调节作用与性别差异，选取443名大学生进行问卷调查。结果表明：（1）被动性社交网站使用通过直接预测与压力知觉的中介作效应两种方式作用于错失焦虑症；（2）乐观调节中介模型的直接路径，在低乐观水平下，被动性社交网站使用对错失焦虑症的预测作用显著；在高乐观水平下，该预测作用不显著；（3）中介效应与调节效应存在性别差异：在女生群体中，压力知觉的中介效应大于男生群体；而乐观的调节效应仅存在于男生群体中。

关键词: 被动性社交网站使用 错失焦虑症 压力知觉 乐观