Groups of friends key to changing health behaviors

Reuters: "People in the small friend groups registered four times as fast as those with less connected networks.

"'It spread through the population so quickly. It saturates very, very fast,' Centola said.

"Social scientists had thought that it would be redundant to give a health message to a person more than once. But Centola said when it comes to health habits, people are quicker to change when they hear the message from more than one source."