In Where Good Ideas Come From, Steven Johnson points out that the most innovative people have broad social networks:
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. In groups united by shared values and long-term familiarity, conformity and convention tended to dampen any potential creative sparks. The limited reach of the network meant that interesting concepts from the outside rarely entered the entrepreneur’s consciousness. But the entrepreneurs who built bridges outside their “islands,” as Ruef called them, were able to borrow or co-opt new ideas from these external environments and put them to use in a new context.