By using videos of children with severe learning disabilities, this study examines understanding of learning disability displayed by the younger siblings of children with learning disabilities as compared with their classmates who have had much less contact with disability. Results indicated that some children from both groups, as young as 3 years, were able to predict the difficulties that would be experienced by a child with a learning disability. Children with a greater level of understanding of the disabled child's difficulties were more likely to be aware of the social difficulties that this child would encounter. Comparing the siblings of children with learning disabilities and their classmates, significantly more siblings showed greater overall understanding of the disabled child's difficulties. The results suggest that it is children's social experiences, and particularly language, that facilitate understanding. Increased understanding leads to changes in the perceived social acceptability of children with learning disabilities.