Children from the first 2 years of life show an awareness that they are either male or female. Later they usually behave in ways culturally appropriate to this awareness. Still later they exhibit a preference for sexual partners of one or the other sex. These three developmental phases, (1) core-morphologic identity, (2) gender role behavior, and (3) sexual partner orientation, constitute sexual identity, a basic personality feature. My concern is with how sexual identity develops. Many strategies exist for answering this question; some will be reviewed here.