I have been thinking about this paper, particularly over the past day:
…Across two studies and two measures of trolling,…[trolls] displayed high levels of the Dark Tetrad [narcissism, Machiavellianism, psychopathy, and sadistic personality] traits and a BFI [Big Five Inventory] profile consistent with those traits. It was sadism, however, that had the most robust associations with trolling of any of the personality measures, including those of the Big Five.
In fact, the associations between sadism and GAIT scores were so strong that it might be said that online trolls are prototypical everyday sadists (Buckels et al., 2013). Note that the Dark Tetrad associations were specific to trolling. Enjoyment of other online activities, such as chatting and debating, was unrelated to sadism. Subsequent analyses confirmed that the Dark Tetrad associations were largely due to overlap with sadism. When their unique contributions were assessed in a multiple regression, only sadism predicted trolling on both measures (trolling enjoyment and GAIT scores). In contrast, when controlling for sadism and the other Dark Tetrad measures, narcissism was actually negatively related to trolling enjoyment. Given that controlling for overall Internet use did not affect these results, personality differences in broader tendencies of Internet use and familiarity cannot explain the findings.
In the final analysis of Study 2, we found clear evidence that sadists tend to troll because they enjoy it. When controlling for enjoyment, sadism’s impact on trolling was cut nearly in half;…
…The Internet is an anonymous environment where it is easy to seek out and explore one’s niche, however idiosyncratic. Consequently, antisocial individuals have greater opportunities to connect with similar others, and to pursue their personal brand of “self expression” than they did before the advent of the Internet.