Background: This study investigated the relative ease of learning across four tasks suggested by an adaptation of Thomas's hierarchy of learning in children with Down syndrome, autism spectrum disorders and mental age-matched controls. Methods: Learning trials were carried out to investigate observational learning, instrumental learning, reversal learning and conditional discrimination. Results: The sample with autism spectrum disorders performed worse than the other two groups on the observational learning and conditional discrimination tasks, while the Down syndrome sample performed worse on the instrumental learning task. Conclusions: These findings are discussed in terms of there implications for reward-based educational intervention programmes.