This article attempts to find useful correspondence between psychoanalytic, psychological, and social observations of sex and gender and the current discoveries in neuroscience related to sex and gender. The author hopes to emphasize that sex and gender are not the same. The current habit of replacing sex with gender adds to the confusion. While sex is very occasionally ambiguous, gender in our current society is inevitably ambiguous. The social descriptors which define gender change almost moment to moment and vary greatly across socioeconomic status. The author hopes to acquaint psychoanalytic readers with some of the relevant information from the neurosciences. It is essential that we as psychoanalysts attend to and use this information in evolving our understanding of the inner psychic world.