Osborn’s most celebrated idea was the one discussed in Chapter 33, “How to Organize a Squad to Create Ideas.” When a group works together, he wrote, the members should engage in a “brainstorm,” which means “using the brain to storm a creative problem—and doing so in commando fashion, with each stormer attacking the same objective.” For Osborn, brainstorming was central to B.B.D.O.’s success. Osborn described, for instance, how the technique inspired a group of ten admen to come up with eighty-seven ideas for a new drugstore in ninety minutes, or nearly an idea per minute. The brainstorm had turned his employees into imagination machines. ...

The underlying assumption of brainstorming is that if people are scared of saying the wrong thing, they’ll end up saying nothing at all. The appeal of this idea is obvious: it’s always nice to be saturated in positive feedback. Typically, participants leave a brainstorming session proud of their contribution. The whiteboard has been filled with free associations. Brainstorming seems like an ideal technique, a feel-good way to boost productivity. But there is a problem with brainstorming. It doesn’t work.