This study explores children's understanding of the causal origins of disabilities. Using a forced-choice explanation task, children's understanding of social-psychological, physical, and biological causal explanations of disabilities was considered. We presented 79 children (26 4- to 5-year-olds, 26 6- to 7-year-olds, and 27 10- to 11-year-olds) with 4 vignettes describing a child with a particular disability (physical disability, blindness, learning disability, attention deficit hyperactivity disorder). Participants rated their agreement with a variety of causal explanations of disability. Results showed significant age, disability, and causal explanation differences in children's causal understandings of disability. Children of all ages showed a preference for physical and biological causes of disability and rejected social-psychological causal explanations. These findings highlight the usefulness of employing a forced-choice methodology to examine young children's concepts of the causal origins of disabilities. (Contains 2 tables.)