One factor that shows insignificant differences between male and female aggression is in sports. In sports, the rate of aggression in both contact and non-contact sports is relatively equal. Since the establishment of Title IX, female sports have increased in competitiveness and importance, which could contribute to the evening of aggression and the "need to win" attitude between both genders. Among sex differences found in adult sports were that females have a higher scale of indirect hostility while men have a higher scale of assault. Another difference found is that men have up to 20 times higher levels of testosterone than women.