Brainstorming is probably the most widely used creativity technique in the world, employed in design firms and science labs, movie studios and classrooms. First proposed by the advertising executive Alex Osborn — the Don Draper of his day — brainstorming is typically described as an ideal template for collaboration, the best way to generate new ideas in a group.

The technique is easy to summarize, since it’s premised on a single assumption: Criticism is bad for the imagination. This is why the very first rule of brainstorming is the prohibition of negative feedback. “Creativity is so delicate a flower that praise tends to make it bloom, while discouragement often nips it in the bud,” Osborn wrote. “In order to increase our imaginative potential, we should focus only on quantity. Quality will come later.”

There is something undeniably appealing about this approach. During a brainstorming session, people are put together in a room and told to free-associate. Before long, the ubiquitous whiteboard is filled with ideas. Everybody has contributed; nobody has been criticized. It’s a feel-good productivity technique.

Alas, the evidence strongly suggests that brainstorming is not effective, at least at generating good ideas. (It can still function as a morale booster.) Study after study has shown that groups engaging in brainstorming come up with fewer good ideas than people working by themselves. In other words, the technique holds us back. Keith Sawyer, a psychologist at Washington University in St. Louis, summarizes the science: “Decades of research have consistently shown that brainstorming groups think of far fewer ideas than the same number of people who work alone and later pool their ideas.”

The reason brainstorming isn’t helpful goes back to Osborn’s prohibition of criticism. Constructive criticism is an important element of group creativity. This is nicely demonstrated by the work of Charlan Nemeth, a psychologist at the University of California at Berkeley. She has repeatedly shown that groups engaging in “debate and dissent” come up with approximately 25 percent more ideas than those engaging in a brainstorm. Furthermore, these ideas are typically rated as more original and useful.

It turns out that the specter of criticism is actually invigorating, prompting us to dig below the surface of our imaginations. And that’s when things get interesting.

The moral is clear: We find our best ideas once we stop pretending that every idea is a good one.

Jonah Lehrer is the author, most recently, of “Imagine: How Creativity Works.”

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