The idea that birth order influences intellectual development and social success has recently been revived, despite the accumulated evidence that birth order effects are often negligible or artifactual. In this paper, the association of birth order with educational attainment is examined among 9,000 Wisconsin high school graduates of 1957 and among their full sibships, including more than 30,000 men and women. Whether selection within the sample of high school graduates, post-secondary educational attainments of those graduates, or educational attainments within full sibships are considered, there are no significant or systematic effects of birth order on educational attainment when other relevant variables have been controlled. Educational attainment appears to increase with birth order when family size is controlled, but this happens because secular increases in schooling have occurred within as well as across families. (Author)