Rules of attraction
Nicholas Christakis, whose research has shown how everything from obesity to smoking to happiness spreads through social networks, said Monday that the human ability to form lasting relationships results from a trade-off between greater access to information provided by our networks and the increased exposure to disease that networks bring. “I think the spread of germs is the price we pay for the spread of information,” Christakis said. “The benefit of a connected life outweighs the cost.” Christakis, who has professorships in sociology, medicine, and medical sociology, provided an overview of how and why social networks form in a talk at the Center for Population and Development Studies. He reviewed recent research on the roots of social groups, including those of Tanzania’s Hadza, among the world’s last hunter-gatherers. Each human network — whether in the midst of the most industrialized societies or in rural Africa — has similar traits, Christakis said. Among them...