Want to make a group smarter? Add women.

You knew that already? Well, now you have proof. A recent study in the journal Science found that if you want to make a group smarter, add women.

Some background: psychologists who have studied individual intelligence know that “general intelligence” can be increased the more a person does something. Individual intelligence can be measured and used to predict how well a person might perform in a variety of tasks.

Does the same hold for groups? Is there a collective intelligence (the ability to perform tasks together)? Can a group become smarter as a group, rather than just as a collection of individuals? The authors of the Science study discovered: yes. Now, you might think that was obvious—add smart people to a group and the group becomes smarter. Not so. The psychologists observed 699 people acting in small groups of two to five members. They solved visual puzzles, completed complex tasks, and brainstormed. Researchers found the intelligence of each group member didn’t significantly affect the group’s intelligence. In fact, adding smart people may have a negative impact on a group’s intelligence. Smart, opinionated people can actually derail a group.

There are three factors that positively affect group intelligence. The first is the group’s average “social sensitivity,” the ability to pick up on emotional cues in others. One might also label this emotional intelligence (EQ). Next, members have more equal turns speaking; conversations aren’t dominated by one or two people. And finally, having a higher number of women members. This last may be because women tend to demonstrate better social sensitivity than men.

What’s the take-away? As study researcher Anita Woolley commented, “…it is becoming less relevant what an individual can do by him or herself and more relevant to understand what individuals can accomplish through others…” If you’re in a position to select group members, make a choice based on social sensitivity rather than individual intelligence alone. Establish guidelines that allow all voices to be heard. In a group not of your own choosing? Make sure to demonstrate your own social sensitivity and to encourage all members to contribute. EQ can be taught; can you push for training to take place?

Which brings us to men in groups. Having more women working together isn’t always possible. But when considering what contributes to a groups success, it might be useful to paraphrase Professor Henry Higgins and ask, “Why can’t a man be more like a woman?”

Citation: “Evidence for a Collective Intelligence Factor in the Performance of Human Groups.” By Anita Williams Woolley, Christopher F. Chabris, Alexander Pentland, Nada Hashmi, Thomas W. Malone. Science, Vol. 329 No. 6000, October 1, 2010.