We don’t follow the herd unless it helps us fit in

Connected The Amazing Power of Social Networks and How They Shape Our Lives

This mysterious attacker would open bedroom windows late at night and spray victims with a “sweet-smelling” anaesthetic gas that would temporarily paralyse them but, even more bizarrely, leave others in the same room unaffected.

Investigators acknowledged the possibility that this evil genius might exist. But they also made clear there was a much more likely explanation — that it was a straightforward case of epidemic hysteria, whereby one person’s emotional fears became contagious in a town of 15,000 people. Epidemic hysteria nowadays goes by the distinctly duller title of mass psychogenic illness (MPI), but the cause and effect remain the same: “Like a single startled buffalo within a herd,” the authors note, “a single emotional reaction in one person can sometimes cause many others to feel the same thing, creating an emotional stampede.”

This is a book about how people influence each other. Mention the words “social network” and one might immediately think of Facebook or Twitter. But this book is about social networks in the wider sense — the myriad ways in which humans are connected to each other, and how those connections shape behaviour and beliefs.

The authors have peppered the book with fascinating examples, ranging from the strange events in Mattoon to Barack Obama’s successful 2008 campaign to the hugely popular online game World of Warcraft.

And so what we get is an incredibly lively and intriguing examination of social networks. As the authors state, how we feel, what we know, whom we marry, whether we fall ill, how much money we make and whether we vote all depends on the ties that bind.

Conventional thinking, for example, would suggest that the best way to reduce smoking is to target smokers with stop-smoking messages. Hence the health warnings on individual cigarette packets.

But it may be more effective to target influential people within a network — regardless of whether they are smokers or not — because of the effect they could have on susceptible people who do smoke.

For that reason, the authors suggest, “understanding the way we are connected is an essential step in creating a more just society and in implementing public policies affecting everything from public health to the economy.

“We might be better off vaccinating centrally located individuals rather than weak individuals. We might be better off persuading friends of smokers of the dangers of smoking rather than targeting smokers. We might be better off helping interconnected groups of people to avoid criminal behaviour rather than preventing or punishing crimes one at a time.”

Radical stuff, explored at rollicking pace. The way we think the world works? It may need revisiting.

- Paul O’Brien is the Irish Examiner’s political editor.