"Cultural historian Ehrenreich explores a human impulse that has been so effectively suppressed that we lack even a term for it: the desire for collective joy, historically expressed in ecstatic revels of feasting, costuming, and dancing. She uncovers the origins of communal celebration in human biology and culture. Although 16th-century Europeans viewed mass festivities as foreign and "savage," Ehrenreich shows that they were indigenous to the West,...