Book excerpt: From tribal religious rituals to the Playboy mansion, and from ancient Rome to Burning Man, Plays Well in Groups explores the phenomenon of group sex. Author Katherine Frank draws on surveys, ethnographic research, participant interviews, and more to provide explanations for both, participation in group sex and our complex reactions to it, from fascination to fear. This book looks at group sex across cultures—who has it, and why. Group sex is almost always taboo and often criminalized, and yet it persists across cultures throughout history. Plays Well in Groups looks at the symbolism of orgies, as well as contemporary manifestations of group sex in bathhouses and public sex venues, at BDSM and swinging parties, on Craigslist, and in political scandals, Tantra classes, reality television, and more. Frank explores the many reasons people participate in group sex, from arousal to spiritual transcendence, in this bold study of subversive sexuality.