To investigate further, Leonie Rösner and Nicole Krämer at the University of Duisburg-Essen in Germany created a fake website for German football fans, and recruited users from a local university.

They then planted a false news story on the site stating that people would no longer be allowed to stand up at football matches. At the time, the idea of banning standing terraces in stadiums was a hot discussion topic in Germany. The researchers then let participants loose on the site’s forum.

Half of these could comment without registering, whereas the others had to use their Facebook accounts to do so. To some participants, all commenters appeared anonymous, while others saw Facebook profiles for everyone.

The forum was also manipulated so that some saw a civil discussion, whereas others were greeted with an atmosphere rich in offensive words, sarcasm, insults and slander – and many exclamation marks.

Rösner and Krämer found that language used by people who were anonymous was not necessarily more aggressive than with people who could be identified. On its own, anonymity is not usually enough to turn people into trolls.

What does seem to make people mean, though, is the behaviour of those around them. The tone set by other commenters was linked to the likelihood that a participant would use aggressive language to support their points

From: Fake football website reveals what makes us become nasty trolls | New Scientist