The average College Board Scholastic Aptitude Test (SAT) scores for women have declined more than the scores for men. Recent evidence concerning the academic performance of men and women was studied by examining sex differences among all SAT takers, test takers grouped by anticipated major field of study, and college freshman year courses and grades. The research was conducted to determine whether there are consistent differences in the intellectual abilities of men and women; whether precollege admissions variables predict college performance with equal accuracy for both sexes; and whether the content or structure of the SAT contributes to observed sex differences in test performance. Neither differences in high school courses and grade point average, major field and career interests, and socioeconomic backgrounds, nor research evidence on differential cognitive functioning, were found sufficient to account for all of the observed sex differences in SAT performance. This study concludes that sex-related SAT differences are very small relative to the generally similar levels of performance by men and women, and that using test scores and high school records to predict first-year college grades continues to be reasonably effective for both sexes. (AUTHOR/DWH). (31pp.)