The Rules of Contagion

one new user per minute during this period. The next day,
researchers at the Tevatron announced that they’d found promising –
but not quite definitive – evidence that the Higgs boson existed. The
Twitter outbreak accelerated, with more and more users joining, and
attention turned to the Large Hadron Collider at CERN. These latest
rumours would prove true: two days later, CERN researchers
announced they had indeed found the boson. As media interest in the
discovery grew, more joined the Twitter outbreak. It grew by over five
hundred users per minute for the next day or so, before peaking soon
after. By 6 July, five days after the first rumour emerged, interest in
the story had declined dramatically.[39]
When the Higgs rumours started, some users posted about the
potential discovery, while others retweeted these comments to their
own followers. If we look at how the first few hundred of these
retweets were connected, there is a huge amount of variation in
transmission (see figure on next page). Most tweets didn’t go very far,
only spreading the news to one or two others. But in the middle of the
transmission network, there is a large chain of retweets, including two
large-scale transmission events, with single users spreading the
rumour to many other people.
This sort of diversity in transmission is common in online sharing.
In 2016, Duncan Watts, then based at Microsoft Research, worked
with collaborators at Stanford University to look at ‘cascades’ of
sharing on Twitter. The group tracked over 620 million pieces of
content, noting which users had reposted links shared by others.
Some links passed between multiple users in a long chain of
transmission. Others sparked but faded away much faster. Some
didn’t spread at all.[40]