This paper examines sex differences in academic underachievement among students who graduated from high school in a western city in 1978. According to data gathered from students' cumulative records for the 7th through 12th grades, males are much more likely than females to have total grade averages and grades in English and mathematics that are lower than would be predicted by their scores on standardized tests of ability. Although the highest achieving females often have lower average ability test scores than the highest achieving males, this results not from the underachievement of the brightest females but from the fact that females with a wide range of ability levels receive good grades and only the very brightest males receive high grades. These sex differences in underachievement appear for middle class and working class students, but often are smaller for the working class and in mathematics grades.In recent years status attainment research has examined influences on males' and females' educational and occupational aspirations and attain-