This study investigated the influence of social support on a person's career choice and its impact on later achievement, testing the hypotheses that social support that pressures a person into entering a given field will lead to lower achievement, and that social support that contributes to the person's development of a professional identity will result in higher achievement. Subjects were 1,156 medical students who entered medical school between 1976 and 1981. In the first year of this program, they answered questionnaires which dealt with their decision to choose medicine as a career. Sixteen items addressed the question of who had given them social support for entering the field. Career related academic achievement was measured with three indicators: scores on the National Board of Medical Examination I and II and the rating for clinical performance during hospital rotations. The findings from this 4-year panel study provides preliminary support for the hypotheses concerning social support. (Author/NB)