ENDLESS meetings that do little but waste everyone’s time. Dysfunctional committees that take two steps back for every one forward. Project teams that engage in wishful groupthinking rather than honest analysis. Everyone who is part of an organization — a company, a nonprofit, a condo board — has experienced these and other pathologies that can occur when human beings try to work together in groups.

But does teamwork have to be a lost cause? Psychologists have been working on the problem for a long time. And for good reason: Nowadays, though we may still idolize the charismatic leader or creative genius, almost every decision of consequence is made by a group. When Facebook’s board of directors establishes a privacy policy, when the C.I.A.’s operatives strike a suspected terrorist hide-out or when a jury decides whether to convict a defendant, what matters is not just the intelligence and wisdom of the individual actors involved. Groups of smart people can make horrible decisions — or great ones.

Psychologists have known for a century that individuals vary in their cognitive ability. But are some groups, like some people, reliably smarter than others?

Working with several colleagues and students, we set out to answer that question. In our first two studies, which we published with Alex Pentland and Nada Hashmi of M.I.T. in 2010 in the journal Science, we grouped 697 volunteer participants into teams of two to five members. Each team worked together to complete a series of short tasks, which were selected to represent the varied kinds of problems that groups are called upon to solve in the real world. One task involved logical analysis, another brainstorming; others emphasized coordination, planning and moral reasoning.