Human beings are likely to adopt the thoughts, beliefs, and behaviors of those around them.
Simple decisions, such as which local store is best to shop at, to more complex decisions, such as vaccinating a child, are influenced by these patterns of behavior and social discourse.
“We choose to be in networks, both online and offline, that are compatible with our own thinking,” explained Amin Rahimian, assistant professor of industrial engineering at the University of Pittsburgh’s Swanson School of Engineering. “Social contagion of behavior through networks can help us understand how and why new norms, products and ideas are adopted.”
Initially, researchers thought that highly clustered ties that are close together in networks created the perfect environment for the spread of complex behaviors that require significant social reinforcement. However, Rahimian, along with a team of researchers from the Massachusetts Institute of Technology (MIT) and Harvard University, contradict these ideas. Long ties, which are created through randomly reconnected edges that make them “longer,” accelerate the spread of social contagions. For example, in the age of social media, long ties can facilitate broader reach across different demographic groups and heterogeneous populations. Instead of simply communicating with one’s neighbor, one can also connect with someone in another state, even another country.
Using mathematical and statistical methods, the researchers were able to analyze the rate of propagation over circular networks with long links and show that having a small probability of adoption below the contagion threshold is enough to guarantee that random rewiring accelerates the spread of these contagions.
“The mechanisms we identified for propagation in circular networks remain valid in higher dimensions,” Rahimian explained.
Similar network dynamics arise in the study of neuronal activity in the brain.
“We are interested in the implications of these results for better understanding the network structures that facilitate the spread of burst activity in various brain regions,” explained Jonathan Rubin, a professor in Pitt’s Department of Mathematics.
This research suggests that those who want to achieve rapid and complete diffusion would benefit from implementing intervention points in network neighborhoods with long-lasting connections to other regions of the network, explained Dean Eckles, associate professor of marketing at MIT. .
“Further work could study these strategies for seeding complex behaviors,” Eckles continued.