The Spread of Obesity among 2,200 individuals. Image from N.A. Christakis and J.H. Fowler, "The Spread of Obesity in a Large Social Network Over 32 Years," New England Journal of Medicine 2007; 35: 370-379

The Spread of Obesity among 2,200 individuals. Image from N.A. Christakis and J.H. Fowler, “The Spread of Obesity in a Large Social Network Over 32 Years,” New England Journal of Medicine 2007; 35: 370-379

 

At the L2 Forum – held yesterday at The Morgan Library – Professor and Co-Director of the Yale Institute of Network Science Nicholas Christakis spoke about the possibilities of intervening in social networks through controlling the flow of information. Christakis, who has an MD and PhD, first studied social networks by looking at clusters of obesity and found that obesity is contagious. He later found that innovation spreads just like diseases, not at random but through networks. Takeaways from his talk:

– There are two ways to intervene in social networks: Changing the Connection (structure) and changing the Contagion (flow).

– An example of manipulating a Connection is turning a network of connections into a neighborhood, where people’s behavior spreads through their immediate neighbors. It’s possible to manipulate a Contagion by deciding who to seed with information.

– If you infect (or incept with information) people at random, spread will remain at levels under control. Seeding the central people, however, will cause spreads at accelerated level.

– These theories have been tested in communities in Honduras, Uganda, Tanzania and India. An experiment with multivitamin pills and chlorine pills in 32 villages in Honduras introduced the interventions to 5% random sample of people in a third of the villages, and 5% with the most connection in another third. In the rest of the villages, people nominated by a random selection of villagers were introduced to the public health ideas. The last group of villages had a 12.2% higher adoption rate of nutritional intervention than the others.

– The structure – or the flow of information – of an organization can change its identity even if the people remain the same. Just like graphite and diamond, which are comprised of the same atoms but are different because of how they are positioned relative to each other.

 

L2's Daily Insights in Your Inbox.