A perfect storm of factors come together to engender the rudeness and aggression seen in the comments’ sections of Web pages, Markman said. First, commenters are often virtually anonymous, and thus, unaccountable for their rudeness. Second, they are at a distance from the target of their anger — be it the article they’re commenting on or another comment on that article — and people tend to antagonize distant abstractions more easily than living, breathing interlocutors. Third, it’s easier to be nasty in writing than in speech, hence the now somewhat outmoded practice of leaving angry notes (back when people used paper), Markman said. [Infographic: A Typical Day on the Internet]

And because comment-section discourses don’t happen in real time, commenters can write lengthy monologues, which tend to entrench them in their extreme viewpoint. “When you’re having a conversation in person, who actually gets to deliver a monologue except people in the movies? Even if you get angry, people are talking back and forth and so eventually you have to calm down and listen so you can have a conversation,” Markman told Life’s Little Mysteries, a sister site to LiveScience.

Chiming in on comment threads may even give one a feeling of accomplishment, albeit a false one.