If Alice is smart, and Bob's even smarter, working together they would A) be twice as smart, B) be half as smart or C) form a task force and get nothing done. According to new research, the answer is none of the above. It would actually depend on how well they get along. What makes a group good at what it does? A team of scientists put their collective heads together and divided volunteers into groups of two to five. And they asked these groups to perform a variety of tasks, from brainstorming answers to questions like "What can you do with a brick?" to team typing blocks of complicated text. What the researchers found is that the intelligence of individual group members was not a good predictor of how well the group as a whole performed. The teams that did best rated high in social sensitivity: their members interacted well, took turns speaking and included more females than groups that did poorly. The study is in the journal Science. So if you're looking for a recipe for group smart, don't automatically reach for the biggest brains. Try adding some heart.