THE AFFECTIVE ROOTS OF CULTURE AND COGNITION WHEN DARWIN WROTE the Origin of Species, he famously closed the book with the provocative promise that “light will be thrown on the origin of man and his history.”۱ In his Descent of Man and his Expression of Emotions in Man and Animals, Darwin began, as promised, to throw some of that light— especially regarding the emotional and cognitive similarities (homologies) of mammals.2 But shortly after this beacon, all went dark again. The rise of positivism in the early twentieth century, paired with the turn toward...