In 2010 researchers from Carnegie Mellon, MIT and Union College published a study of 699 people working in small groups in the journal Science. They found a “general collective intelligence factor” that explained how well a group did across many tasks. It was linked to “the equality in distribution of conversational turn-taking.”
The lead author, Anita Williams Woolley, said that “in groups where one person dominated, the group was less collectively intelligent than in groups where the conversational turns were more evenly distributed.”