We reviewed eight studies that described learning differences between students with learning disabilities (LD) and students with mild mental retardation (MMR). A total of 639 students, 6-20 years old, participated in these studies. Study authors examined students' inductive reasoning and their performance during guided inquiry and more lengthy interventions in reading and math. Students with LD and students with MMR were assessed in terms of learning ease, pre- to posttreatment gains, and the maintenance, transfer, and application of knowledge acquisition. Students with LD statistically significantly outperformed students with MMR on both inductive reasoning and guided inquiry tasks. They made reliably larger gains following interventions in reading and math. Across all learning tasks and contexts, students with LD displayed greater consistency transferring and applying conceptual knowledge to new tasks. Regarding maintenance, results were mixed. Implications for categorical instruction are discussed.