“Researchers at Carnegie Mellon … provided the first direct evidence for a fixed collective intelligence in groups. Interestingly, factors you might assume made smart groups – including group cohesion, motivation, and satisfaction – had no effect. But there were three things that across many studies created smarter groups: (1) social sensitivity; (2) little variance in members’ number of speaking turns – the conversation wasn’t dominated by one voice; and (3) the proportion of members who were female – though this was due in part to social sensitivity.”
(This research, summarized by Garth Sundem in Brain Trust)
A friend sent me a related article from the New York Times Magazine, “What Google Learned From Its Quest to Build the Perfect Team”.