“Of course, no one has to stand, but I’d rather have a clear default setting. The split-second call of whether to stand or sit can designate you a groupie or a grinch, turning each spectator into a customer taking a satisfaction survey, a Roman emperor delivering the gladiator a thumbs-up or thumbs-down. By eliminating the choice and going with the flow, you leave more room for contemplating the play (or where you’re going to get dinner afterward). And if the choice falls between withholding gratitude or giving it, why not err on the side of generosity without feeling shamed?”