When it comes to social influence, what type of people lead and who follows? It’s a question pondered by parents and marketing companies alike. Researchers at NYU sought to figure it out by tracking more than a million users on Facebook.
Sinan Aral, a NYU Stern assistant professor of information, operations and management sciences, and Dylan Walker, a research scientist at Stern, started out with 7,730 users of a single Facebook app that allowed them to rate movies, actors and other Hollywood types. Each time the user rated something, Facebook would randomly send a message to some of that user’s friends with the user’s rating and information about the app — about 42,000 messages were sent to 1.3 million friends. The idea was to see who among the network was mostly likely to be convinced to try the app too.
Overall, the researchers found, the app wasn’t overwhelmingly popular. Just under 1,000 people signed up to use the app. But the scientists were still able to see how influence spread and pick out certain patterns in who was mostly likely to influence whom.
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Among the study’s findings:
—Men are overall 49% more influential than women, but women are 12% less susceptible to influence than men
—Women exert 46% more influence over men than over other women
—Single and married people are more influential than others:
- Single people are 113% more influential than people “In a relationship” and 128% more influential than those whose status reads “It’s complicated”
- Married people are the most influential people of all: 140% more so than those in a relationship and 158% more than the “It’s complicated” group
—”It’s complicated” types were the least influential and the most likely to be influenced by others; the opposite was true for married folks, who are not only the most influential, but also the least susceptible to others’ influence
—Older people — anyone over 30 — are more influential and less susceptible to influence than younger people
—Influence and susceptibility seem to be mutually exclusive: highly influential people are not susceptible, and highly susceptible people aren’t influential
—Some people are significantly more influential than others and they tend to be clustered in networks with other highly influential people, giving them the potential to be “super-spreaders” of influence; less susceptible — or more stubborn — people also tend to cluster together
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The study avoided a common pitfall of other research on social networks — the homophily bias — by randomizing which friends received updates from the app. Homophily refers to similarities shared by people who are friends and belong to the same social network. “If two friends adopt a product or behavior one after the other, current methods have a hard time distinguishing whether it’s because of peer influence, or rather, that the friends simply have similar preferences and thus behave similarly,” says Walker.
Still, the study looked only at one app, and the researchers caution that further study is needed to better understand the nature of influence.
There are several philosophies for how information, ideas and products spread through a society. Some theorists believe that a small number of influential people wield control, while others argue it is through many susceptible people that ideas are passed. Based on the current findings, the authors conclude that, “it is the joint distribution of both influence and susceptibility in the network which together determine the pattern of the contagion and someone’s importance to the propagation of behaviors in a population.”
The findings have obvious value for the advertising industry, but the researchers note that there’s more to be taken from their study. “While our research is certainly important for targeted advertising and viral marketing, the domain of application is not just limited to products, but can also be used for social good,” says Walker. “We’re now working on applying the same science to promote HIV testing in Africa and other positive behaviors like exercise and political awareness.”
The study was published in the journal Science.