As part of the Stanford Curriculum Study, information is provided on sex differences in undergraduate students' characteristics and performance. Attention is directed to the effect of gender on major choice, classroom performance, awards earned at graduation, and related variables for graduates from 1975-1976 to 1981-1982. A comparison to national trends is also made. The findings indicate that there is considerable conformity to sex stereotypes among Stanford students in the majors they select and their classroom performance. Women come to Stanford with lower mathematics ability than men and are strongly influenced by their established abilities in their choice of major. Women tend to concentrate in the humanistic and social science areas while men favor engineering, the natural sciences, and several traditionally-male disciplines in other areas. On the whole, women at Stanford are similar to women in the nation in their degree of conformity to traditional sex differentiation. In addition, women perform less well in natural science and engineering courses; however, poorer performance by women in technical courses is limited mostly to introductory courses. The proportion of women in engineering and the earth sciences increased rapidly in the late 1970s. (SW)