Abstract
Social networking site (SNS) use is common and speculation about the negative impact of SNS use on mental health and psychological well-being is a recurring theme in scientific debates. The evidence for this link, however, is inconclusive. The Fear of Missing Out (FoMO) may assist in understanding the mixed evidence, as individuals who experience FoMO are more driven to keep up with what is happening to avoid missing out. We used a 2-week daily diary study of 408 university students to measure the daily associations between SNS use and negative and positive affect and whether FoMO moderated these associations. Multi-level Bayesian regression analyses revealed that 1) greater SNS use was associated with reductions in successive positive affect, but not increases in negative affect and 2) FoMO moderated the influence of SNS use such that increases in successive negative affect occurred only in those individuals high in trait FoMO.