Many observers believe that intellectual ability has become a more important determinant of occupational success in recent decades and that social-class differences in ability have consequently increased. This article examines changes in occupational-class differences in scores on a test of verbal ability for people born between the late 19th century and the 1960s. Contrary to the usual view, class differences have become smaller among people born after about 1945; this development reflects changes in the quantity and the effects of education. Therefore, current social problems cannot be ascribed to an increasing concentration of low-ability people in the lower classes.