A study examined the differential effects of experiences prior to labor force entry, primarily in high school, on the later sex-typicality of occupations and earnings of non-college-bound men and women. The study analyzed data from the National Longitudinal Surveys of the Labor Market Experiences of Young Men and Women. (These surveys lnvolved some 5,000 young men and 5,000 young women aged fourteen to twenty-four in 1968.) Through interviews that were conducted annually with these respondents between 1968 and 1978, information was obtained concerning respondent demographic characteristics, schooling and job training, attitudes and aspirations, and school experiences and school characteristics. Data revealed that sex-related differences in occupational choices depend upon differences in aspirations that predate high school entry. Schools serve primarily to reinforce sex-typed values as well as general and work-related values of parents and society. Occupational training in high school does have short term positive effects on labor force outcomes for both sexes. However, in the long run, being in traditionally female occupational programs is detrimental to white women. Black women in commercial programs fare better. Recommendations call for affirmative action for adults to provide role models for children. (Appended survey data constitutes approximately one-third of the report.) (MN)