“It was sadism, however, that had the most robust associations with trolling of any of the personality measures,” said psychologists from the University of Manitoba, University of Winnipeg and University of British Columbia in an article published in the ‘Personality and Individual Differences’ journal.

It went on to claim that trolls are “agents of chaos” that exploit “hot-button issues” to inflame and exploit users’ emotions,

"If an unfortunate person falls into their trap, trolling intensifies for further, merciless amusement. This is why novice Internet users are routinely admonished, 'Do not feed the trolls!'," the study warned.

http://www.independent.co.uk/life-style/gadgets-and-tech/news/online-trolls-are-psychopaths-and-sadists-psychologists-claim-9134396.html