To grow and innovate, organizations have to come up with creative ideas. At the employee level, creativity results from a combination of expertise, motivation, and thinking skills. At the team level, it results from the synergy between team members, which allows the group to produce something greater than the sum of its parts.

The most widely used method to spark group creativity is brainstorming, a technique first introduced by Alex Osborn, a real life “Mad Man,” in the 1950s. Brainstorming is based on four rules: (a) generate as many ideas as possible; (b) prioritize unusual or original ideas; (c) combine and refine the ideas generated; and (d) abstain from criticism during the exercise. The process, which should be informal and unstructured, is based on two old psychological premises. First, that the mere presence of others can have motivating effects on an individual’s performance. Second, that quantity (eventually) leads to quality.

Osborn famously claimed that brainstorming should enhance creative performance by almost 50% versus individuals working on their own. Yet after six decades of independent scientific research, there is very little evidence for the idea that brainstorming produces more or better ideas than the same number of individuals would produce working independently. In fact, a great deal of evidence indicates that brainstorming actually harms creative performance, resulting in a collective performance loss that is the very opposite of synergy.

You and Your Team Meetings How to make them more productive.

A meta-analytic review of over 800 teams indicated that individuals are more likely to generate a higher number of original ideas when they don’t interact with others. Brainstorming is particularly likely to harm productivity in large teams, when teams are closely supervised, and when performance is oral rather than written. Another problem is that teams tend to give up when they notice that their efforts aren’t producing very much.

But why doesn’t brainstorming work? There are four explanations:

Social loafing: There’s a tendency – also known as free riding – for people to make less of an effort when they are working in teams than alone. As with the bystander effect, we feel less propelled to do something when we know other people might do it.

Social anxiety: People worry about other team members’ views of their ideas. This is also referred to as evaluation apprehension. Similarly, when team members perceive that others have more expertise, their performance declines. This is especially problematic for introverted and less confident individuals.

Regression to the mean: This is the process of downward adjustment whereby the most talented group members end up matching the performance of their less talented counterparts. This effect is well known in sports – if you practice with someone less competent than you, your competence level declines and you sink to the mediocrity of your opponent.

Production blocking: No matter how large the group, individuals can only express a single idea at one time if they want other group members to hear them. Studies have found that the number of suggestions plateaus with more than six or seven group members, and that the number of ideas per person declines as group size increases.

Given brainstorming’s flaws, why is the practice so widely adopted?

There are two main reasons. First, with the increased specialization of labor, organizations see that expertise is distributed among their employees. If problem-solving benefits from different types of knowledge, assembling the right combination of people should, in theory, increase the amount of expertise in the room and result in better solutions being proposed. However, in practice, this approach would require careful selection of individuals and painstaking coordination of their efforts. Second, even though groups don’t generate more or better ideas, brainstorming is arguably more democratic than the alternatives, so it can enhance buy-in and subsequent implementation of the ideas generated, regardless of the quality of those ideas.

Ultimately, brainstorming continues to be used because it feels intuitively right to do so. As such, it is one more placebo in the talent management cabinet, believed to work in spite of the clear absence of evidence. So go ahead, schedule that brainstorming meeting. Just don’t expect it to accomplish much, other than making your team feel good.