A study was conducted to determine how children in preschool/kindergarten and third/fourth grades would predict whether a boy or a girl would succeed on cohort-defined masculine, feminine, or sex-neutral tasks. Older children predicted the winners along sex-typed dimensions. Boys and girls predicted a male more frequently when the task was masculine, a female when the task was feminine, and a male as often as a female when the task was sex-neutral. Children were also asked to explain their attributions of success by selecting among four factors: ability, effort, task ease, and luck. For children of both grade levels, female success on a masculine task was attributed to effort, not ability. Furthermore, luck was used more frequently to explain the success of an unexpected winner than an expected one. Results obtained with children therefore support attribution theory and previous research with adults. (Author/RH)