The uncertainty of teasing, as Stanford’s Robert Sapolsky established, spikes dopamine 400 percent. Nipple stimulation boosts oxytocin. Pressure in the throat or colon regulates the vagus nerve,23 creating exhilaration, intense relaxation, and goose bumps, what Princeton gastroenterologist Anish Sheth memorably terms poo-phoria. “To some it may feel like a religious experience,” Sheth writes, “to others like an orgasm, and to a lucky few like both.”
