This study found that 10 adolescents with mental retardation processed stimuli varying with respect to symmetry in comparable manner to peers matched for mental age and chronological age. Results argue for the robustness of the symmetry effect across groups differing in intelligence and physically dissimilar stimulus types (checkerboard versus…

Detection differences between 16 mildly mentally retarded and 14 nonretarded students aged about 16 years were studied via the presentation of high, intermediate, and low stimulus organizations of target and distractor stimuli. Implications for explaining intelligence-related differences across a range of tasks are discussed. (SLD)