The Rules of Contagion

In some cases, people have decided to exploit the context collapse
that occurs online. Although ‘trolling’ has become a broad term for
online abuse, in early internet culture a troll was mischievous rather
than hateful.[28] The aim was to provoke a sincere reaction to an
implausible situation. Many of Jonah Peretti’s pre-BuzzFeed
experiments used this approach, running a series of online pranks to
attract attention.
Trolling has since become an effective tactic in social media
debates. Unlike real life, the interactions we have online are in effect
on a stage. If a troll can engineer a seemingly overblown response
from their opponent, it can play well with random onlookers, who may
not know the full context. The opponent, who may well have a
justified point, ends up looking absurd. ‘O Lord make my enemies
ridiculous,’ as Voltaire once said.[29]
Many trolls – of both the prankster and abuser kinds – wouldn’t
behave this way in real life. Psychologists refer to it as the ‘online
disinhibition effect’: shielded from face-to-face responses and real-life
identities, people’s personalities may adopt a very different form.[30]
But it isn’t simply a matter of a few people being trolls-in-waiting.
Analysis of antisocial behaviour online has found that a whole range
of people can become trolls, given the right circumstances. In
particular, we are more likely to act like trolls when we are in a bad
mood, or when others in the conversation are already trolling.[31]
As well as creating new types of interactions, the internet is also
creating new ways to study how things spread. In the field of
infectious diseases, it’s generally not feasible to deliberately infect
people to see how something spreads, as Ronald Ross tried to do
with malaria in the 1890s. If modern researchers do run infection
studies, they are usually small, expensive, and subject to careful
ethical scrutiny. For the most part, we have to rely on observed data,
using mathematical models to ask ‘what if?’ questions about
outbreaks. The difference online is that it can be relatively cheap and
easy to spark contagion deliberately, especially if you happen to run a
social media company.