If psychoanalytic claims about motivation are correct, we should be able to relate them to those of other disciplines, such as social psychology, developmental psychology, evolutionary psychology and neuroscience. In what follows I try to indicate some interdisciplinary links, by relating evolutionary and psychoanalytic discussions of emotion and infancy. The theory of natural selection gives us some idea of the main forces which have shaped basic aspects of the human mind (or brain). In so far as we can align these with psychoanalytic understanding, we may hope to triangulate more accurately on the points of connection between.