Studies have shown that performance gets worse as group size increases: groups of nine generate fewer and poorer ideas compared to groups of six, which do worse than groups of four. The “evidence from science suggests that business people must be insane to use brainstorming groups,” writes 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 one exception to this is online brainstorming.

Theodor Geisel (otherwise known as Dr. Seuss) spent his workdays ensconced in his private studio, the walls lined with sketches and drawings, in a bell-tower outside his La Jolla, California, house. Geisel was a much more quiet man than his jocular rhymes suggest. He rarely ventured out in public to meet his young readership, fretting that kids would expect a merry, outspoken, Cat in the Hat–like figure, and would be disappointed with his reserved personality. “In mass, [children] terrify me,” he admitted.

It makes sense that so many introverts hide even from themselves. We live with a value system that I call the Extrovert Ideal — the omnipresent belief that the ideal self is gregarious, alpha, and comfortable in the spotlight. The archetypal extrovert prefers action to contemplation, risk-taking to heed-taking, certainty to doubt. He favors quick decisions, even at the risk of being wrong. She works well in teams and socializes in groups. We like to think that we value individuality, but all too often we admire one type of individual — the kind who’s comfortable “putting himself out there.