Three-person groups best for problem-solving

What is the optimum group size for logic-based problem solving?

It seems 3-person groups work best. That’s according to Patrick Laughlin and colleagues who tested 760 students on a series of 'letters-to-numbers' logic problems. For each of problems, the performance of students working alone was compared with the performance of a 2-, 3-, 4-and 5-person group working on the same problem.

The 2-person groups didn’t tend to perform any better than the best of 2 students who were working alone on the same problem. However, the 3, 4 and 5-person groups consistently outperformed the best of 3, 4 or 5 individuals working alone on the same task. The groups solved the problem more quickly and used more sophisticated equations.

However, the 4- and 5-person groups were no better than the 3-person groups, suggesting a team of three is the optimum group size for logic-based problem solving. “If groups of three perform as well as groups of larger size, it is obviously a more efficient use of human and logistic resources to use 3-person groups”, the researchers concluded.

Source: Journal of Personality and Social Psychology, 90, 644-651.