Two studies used a structural equation model to examine the relationship between gender and participation in college mathematics, physics, and chemistry courses. The intervening variables under scrutiny were ability scores, attitudes toward mathematics and mathematicians, and expectations of future performance in physical science courses. The paths which best explained the connection were (1) Sex/Ability/Expectations/Participation, and (2) Sex/Ability/Attitudes/ Expectations/Participation. In no case was gender a direct cause of participation, but in all cases explanatory paths involved variables influenced by the process of socialization. Thus, to increase women's participation, this model suggests that interventions oriented toward giving them more skills, creating more positive attitudes and creating higher expectations would all be effective. (Author)