What Ruef discovered was a ringing endorsement of the coffeehouse model of social networking: the most creative individuals in Ruef’s survey consistently had broad social networks that extended outside their organization and involved people from diverse fields of expertise. Diverse, horizontal social networks, in Ruef’s analysis, were three times more innovative than uniform, vertical networks.
A similar study, conducted by a University of Chicago business school professor named Ronald Burt, looked at the origin of good ideas inside the organizational network of the Raytheon Corporation. Burt found that innovative thinking was much more likely to emerge from individuals who bridged “structural holes” between tightly knit clusters. Employees who primarily shared information with people in their own division had a harder time coming up with useful suggestions for Raytheon’s business, when measured against employees who maintained active links to a more diverse group.
– Via Steven Johnson's Where Good Ideas Come From: The Natural History of Innovation