David and Goliath: Underdogs, Misfits, and the Art of Battling Giants

by Malcolm Gladwell

My perfect number is eighteen: that’s enough bodies in the room that no one person needs to feel vulnerable, but everyone can feel important. Eighteen divides handily into groups of two or three or six—all varying degrees of intimacy in and of themselves. With eighteen students, I can always get to each one of them when I need to. Twenty-four is my second favorite number—the extra six bodies make it even more likely that there will be a dissident among them, a rebel or two to challenge the status quo. But the trade-off with twenty-four is that it verges on having the energetic mass of an audience instead of a team. Add six more of them to hit thirty bodies and we’ve weakened the energetic connections so far that even the most charismatic of teachers can’t maintain the magic all the time.