Young adults were studied for internalized aggression by a projective technique [Rosenzweig Picture Frustration (PF) Study] and externalized aggression by a questionnaire [Yatabe-Guilford (YG) Personality Inventory]. Subjects were 293 students, 8fi men and 247 women (mean age, 18.9 years). Extrapunitive scores measured by PF (PF-E) were divided into high and non-high, and the YG aggression (Ag) scale was divided into high, middle, and low. In the subjects with high PF-E scores, the gender difference in the distribution of the Ag score was great. In men, internalized and externalized aggression were correlated. In women, Ag scores had two peaks, in the high and low areas. Men expressed aggression in an uncomplicated way and women in a complicated way, some with high levels of internalized aggression expressing it and some repressing it. That aggression in these women was not always inhibited reflects recent changes in the psychology of Japanese women.