Half a century ago, student activists liberated themselves—partly, at least—from in loco parentis: the paternalistic notion that college administrators should serve as watchful guardians, restricting students’ activities and rights in order to provide a safe environment for them, the way a mother or father would. Today, students across the country are determined to undo this liberation. At Yale University, a group of aggrieved minority students have demanded the resignations of administrators who wisely rejected calls for emotional coddling. Nicholas Christakis, the master of Yale’s Silliman College, and his wife, Erika Christakis, an early childhood educator at Yale, conveyed to students...