Conversely, brainstorming sessions are one of the worst possible ways to stimulate creativity. The brainchild of a charismatic advertising executive named Alex Osborn who believed that groups produced better ideas than individuals, workplace brainstorming sessions came into vogue in the 1950s. “The quantitative results of group brainstorming are beyond question,” Mr. Osborn wrote. “One group produced 45 suggestions for a home-appliance promotion, 56 ideas for a money-raising campaign, 124 ideas on how to sell more blankets.” But decades of research show that individuals almost always perform better than groups in both quality and quantity, and group performance gets worse as group size increases. The “evidence from science suggests that business people must be insane to use brainstorming groups,” wrote the organizational psychologist Adrian Furnham. “If you have talented and motivated people, they should be encouraged to work alone when creativity or efficiency is the highest priority.” The reasons brainstorming fails are instructive for other forms of group work, too. People in groups tend to sit back and let others do the work; they instinctively mimic others’ opinions and lose sight of their own; and, often succumb to peer pressure. The Emory University neuroscientist Gregory Berns found that when we take a stance different from the group’s, we activate the amygdala, a small organ in the brain associated with the fear of rejection. Professor Berns calls this “the pain of independence.”