Yale professor Tamar Gendler continues her course Philosophy and the Science of Human Nature (PHIL 181) with a lecture on social attachment and moral behavior. She opens with Stanley Milgram's obedience experiments, noting that subjects were more likely to administer harm when the authority figure was physically close and the victim distant, and asks what proximity does to moral judgment. The lecture then turns to Harry Harlow's wire mother and cloth mother experiments on rhesus monkeys, studies of infant attachment styles, and cross cultural research linking social relationships to health and flourishing. Recorded in Spring 2011, the talk runs just under forty minutes and closes with a student question period. It builds toward an argument that human wellbeing depends on attachment bonds formed early and sustained across a life, using classic psychology experiments as evidence for a philosophical claim about human nature.