The modern-day influence economy would have us believe that the best way to sell a product – or an idea – is to have an influencer, at the centre of a network of social connections, promote it for you. But new research from the University of Pennsylvania (Penn), published today in Nature Communications, suggests the best way to spread a message or idea is to launch it in the periphery of a social network, among less prominent figures.
“When social influencers present ideas that are dissonant with their followers’ world views – say, for example, that vaccination is safe and effective – they can unintentionally antagonise the people they are seeking to persuade because people typically only follow influencers whose ideas confirm their beliefs about the world,” says Damon Centola, professor of communication, sociology, and engineering at Penn, and senior author on the paper.
Despite having a predicted value of around US$13.8 billion in 2021, the global influencer economy may therefore not be the strongest agent for behavioural change. Instead, the authors argue that the most powerful way to plant new ideas is to target people or groups in the outer fringes of a network.
Centola and co-author Douglas Guilbeault studied more than 400 public health networks to discover which people could spread new ideas and behaviours most effectively. They tested every possible person in every network to determine who would be most effective for spreading everything from celebrity gossip to vaccine acceptance.
“Dozens of algorithms that are currently used by enterprises seeking to spread new ideas are based on the fallacy that everything spreads virally,” says Centola. “But this study shows that the ability for information to pass through a social network depends on what type of information it is.”
The research found that uncontroversial, easily digestible information can spread conventionally from the centre out, via powerful influencers or thought leaders. Contested beliefs and newer ways of thinking, on the other hand, are most transmissible when they originate from the periphery.
“Our big discovery is that every network has a hidden social cluster in the outer edges that is perfectly poised to increase the spread of a new idea by several hundred percent,” says Centola. “These social clusters are ground zero for triggering tipping points in society.”
The authors applied their findings to predict the spread of a microfinance program across communities in India, and found that they could predict where it should originate from, and whether it would spread to the rest of the population. The researchers found they could pinpoint which individual would be able to most influence the adoption of the new program by others.
Guilbeault, now an assistant professor at the University of California, Berkeley, notes that “in a sense, we found that the centre of the network changed depending on what was spreading. The more uncertain people were about a new idea, the more that social influence moved to the people who only had parochial connections, rather than people with many far-reaching social connections.
“The people in the edges of the network suddenly had the greatest influence across the entire community.”
This isn’t an entirely unfamiliar idea. In 2019, a study from the University of Oxford, UK, found that people who form smaller, tight-knit groups of friends may end up being more powerful social influencers than those with many, looser connections because their influence within their own cliques can trigger a rapid spread of new ideas and behaviours.
Centola says the findings “turn our notions about social influence for marketing, sales and social movements upside down”.
This type of thought engineering may seem eerily dystopian, but it’s actually a common tool used by marketing experts, policymakers and activists.
“Not everything spreads through a network in the same way, and we can use this knowledge to pinpoint hotspots in the social graph,” says Centola. “This can allow us to accurately tailor our network strategies for effecting positive social change.”
Amalyah Hart is a science journalist based in Melbourne.
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