The research by Lancaster University in UK, suggests that those who engage in trolling - Internet user behaviour that is meant to intentionally anger or frustrate someone else in order to provoke a response - do so for their own amusement and because they are bored.
Dr Claire Hardaker, a linguistics expert from the University's Faculty of Arts and Social Sciences, studied almost 4,000 online cases involving claims of trolling, The Independent reported.
Trolls operate out of a feeling of power, amusement, boredom and revenge and thrive on the anonymity which the internet provides, she found.
The research identified seven tactics used by trolls to bombard their victims with insults and threats.
The seven tactics include digressing from the topic at hand, especially onto sensitive topics, and hypocriticising - pedantic criticism of grammar, spelling or punctuation in a post which itself contains proof-reading errors.
Antipathising, by taking up an alienating position, asking pseudo-naive questions is another tactic used by trolls besides giving dangerous advice and encouraging risky behaviour.
Trolls also employ 'shock strategy' by being insensitive about sensitive topics, explicit about taboo topics, etc. They also provoke others by insulting or threatening them.
They may cross-post - sending the same offensive or provocative message to multiple groups then waiting for the response.
"Aggression, deception and manipulation are increasingly part of online interaction, yet many users are unaware not only that some of these behaviours exist, but of how destructive and insidious they can be," Hardaker said.
She also found that while trolling is associated with the young, trolls come from all ages and backgrounds.
"An incredible amount of time and strategy can be involved in trolling, as my research into the techniques they use highlights," she said.
She warned that trolling can in some cases develop into more serious behaviour, including cyberharassment and cyberstalking.
The study was published in the Journal of Language, Aggression and Conflict.