The Rules of Contagion

contagious event and another – known in epidemiology as the
‘generation time’ – is relatively short. Some clusters of suicides have
involved multiple deaths over a matter of weeks: in 1989 there was
an outbreak of suicides at a Pennsylvania high school, which saw
nine attempts in eighteen days. If these events were the result of
contagion, the generation time may in some cases have been only a
few days.[16]
Clustering is common with other types of violence too. In 2015, a
quarter of US gun murders were concentrated in neighborhoods that
made up less than 2 per cent of the country’s overall population.[17]
When Gary Slutkin and his colleagues set out to tackle violence as if
it were an outbreak, it was neighbourhoods like these that they
planned to target. They called the initial programme ‘CeaseFire’; this
would later evolve into a larger organisation called Cure Violence. In
those early days, it took a while to work out precisely what approach
they should use. ‘We took five years of strategy development before
we put a single thing on the street,’ Slutkin said. The Cure Violence
method would end up having three parts. First, the team hires
‘violence interrupters’ who can spot potential conflicts and intervene
to stop the transmission of violence. Someone might end up in
hospital with a gunshot wound, for example, and an interrupter will
step in to talk their friends out of a retaliatory attack. Second, Cure
Violence identifies who is at greatest risk of violence, using outreach
workers to encourage a change in attitudes and behaviour. This can
include help with things like job hunting or drug treatment. Finally, the
team works to change social norms about guns in the wider
community. The idea is to have a range of voices speaking out
against a culture of violence.
Interrupters and outreach workers are recruited directly from the
affected communities; some are former criminals or gang members.
‘We hire workers who are credible with that population,’ said Charlie
Ransford, Cure Violence’s Director of Science and Policy. ‘To change
people’s behaviour and talk them out of doing something it helps if
you have an understanding of where they’re coming from, and they
feel like you have an understanding and maybe even know you or
know someone who knows you.’[18] This is another idea familiar in