The first empirical test of Osborn’s brainstorming technique was performed at Yale University, in 1958. Forty-eight male undergraduates were divided into twelve groups and given a series of creative puzzles. The groups were instructed to follow Osborn’s guidelines. As a control sample, the scientists gave the same puzzles to forty-eight students working by themselves. The results were a sobering refutation of Osborn. The solo students came up with roughly twice as many solutions as the brainstorming groups, and a panel of judges deemed their solutions more “feasible” and “effective.” Brainstorming didn’t unleash the potential of the group, but rather made each individual less creative.
Unfortunately, Lehrer's column draws some misleading conclusions as well. Scott Berkun, author of Mindfire: Big Ideas For Curious Minds, has written a strong rebuttal to Lehrer's essay. Berkun offers four key criticisms of Lehrer's conclusions:
1. Nothing matters if the room is filled with morons or strangers (or both).
2. Brainstorming is designed for idea volume, not depth or quality.
3. The person leading an idea generation session matters.
4. Generating ideas is a small part of the process.
Berkun takes particular issue with the conclusions that Lehrer draws from a study by Charlan Nemeth. Brainstorming typically involves a shared norm called "deferred judgment." Under that norm, participants do not criticize each others' ideas during the idea generation process. Berkun explains Nemeth's study:
The primary thrust of Lehrer’s critique is based on a 2003 study by Nemeth, where students were divided into groups and given 3 different sets of instructions. In one group, no instruction was given (‘Minimal’). In the second group, basic brainstorming rules were given (‘Brainstorming’). In the last, brainstorming rules were given, plus students were allowed to critique each others ideas (‘Debate’).... The results do show that the group that could critique generated more ideas... [However] The debate groups was given brainstorming instructions, as well as an instruction to debate. It should be labeled “Brainstorming with debate“. If the only instruction they were given was to debate, it’d be a fair comparison. But it isn’t.
Lehrer concludes from this Nemeth study that stimulating dissent and debate works much more effectively than brainstorming. I'm with Berkun - that conclusion is a step too far. My work over the past fifteen years has focused a great deal on the importance of debate and dissent. I'm glad that Lehrer has chosen to emphasize its importance. However, an effective group process doesn't employ either deferred judgment or dissent and debate. It involves both! In the idea generation phase, deferred judgment makes sense as a norm employed to encourage the generation of many different ideas and options. Later, dissent and debate become critical as a means of comparing and contrasting those options, and perhaps facilitating the development and generation of more ideas and alternatives.
One final point - Later in the article, Lehrer describes the many innovations that emerged from Building 20 at MIT over the years. He concludes, "The lesson of Building 20 is that when the composition of the group is right—enough people with different perspectives running into one another in unpredictable ways—the group dynamic will take care of itself." In other words, if you get the team composition right, you will automatically get lots of constructive dissent and debate. I disagree wholeheartedly with this conclusion. It's just not right. You do not guarantee constructive dissent and debate simply by building a diverse team and giving them a forum for dialogue. In many settings, people simply don't speak up. Groupthink occurs even in diverse teams at times. Yes, you have to get the composition right, but group dynamics do not take care of themselves. They take hard work on the part of a leader. Leadership matters! Process matters!