When 'friends' collide: Social heterogeneity and user vulnerability on social network sites

The present study examines how the use of social network sites (SNS) increases the potential of experiencing psychological, reputational and physical vulnerability online. From our theoretical perspective, concerns over the use of social network sites and online vulnerability stem from the ease with which users can amass large and diverse sets of online social connections and the associated maintenance costs. To date most studies of online vulnerability have relied on self-report measures, rarely combining such information with user's validated digital characteristics. Here, for a stratified sample of 177 UK-based Facebook users aged 13 to 77, digitally derived network data, coded for content and subjected to structural analysis, were integrated with self-report measures of social network heterogeneity and user vulnerability. Findings indicated a positive association between Facebook network size and online vulnerability mediated by both social diversity and structural features of the network. In particular, network clustering and the number of non-person contacts were predictive of vulnerability. Our findings support the notion that connecting to large networks of online 'friends' can lead to increasingly complex online socialising that is no longer controllable at a desirable level.