Three studies investigated preschoolers' reasoning about ability. Findings suggested sensitivity to mental state information when judging another child's ability, and they perceived positive correlations between effort and academic success, and "niceness" and high academic ability. Comparisons with 9- to 10-year-olds suggest that preschool findings reflect emerging reasoning patterns that persist, but that correlations between effort and academic outcomes and between social and academic traits diminish with age. (Author/KB)