Anita Woolley of Carnegie Mellon and several of her colleagues have conducted a fascinating new study on group intelligence, which they just published in the journal Science. The scholars found that a group's ability to perform certain cognitive tasks is not correlated with the individual intelligence of team members. (It's also not correlated with motivation or happiness of individual members.) In fact, groups that deferred to an apparent expert in the group tended to not do so well on these tasks. Instead, groups with more balanced participation tended to perform well. Moreover, they found that groups with a higher proportion of women tended to do well.
Why do groups with more women perform better? Woolley explains that it's not so much about gender in and of itself that drives performance, but the fact that women tend to have a higher degree of social sensitivity. By that, she means that they are more able to identify and react to emotional cues during a group conversation. That social sensitivity tends to insure that people with diverse perspectives and knowledge all speak up and contribute to the team conversation. That balanced, open dialogue enhances group performance on cognitive tasks.