title: The effects of social reinforcement and task difficulty level on the pleasure derived by normal and retarded children from cognitive challenge and mastery.
mesh_terms: D002648:Child; D002755:Choice Behavior; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000523:psychology*; D008297:Male; D010549:Personal Satisfaction; D011340:Problem Solving; D012056:Reinforcement, Social; D012737:Sex Factors; D013647:Task Performance and Analysis