Thirty-six retarded and 36 nonretarded children and adolescents, individually matched for mental age, were given discrimination problems at two levels of stimulus complexity to test the hypothesis that retarded persons require more trials to reach criterion on the more complex problems. (Author)

Two groups of mentally retarded children (MA: 4 to 8 years) were pretrained using two different methods. It was predicted that shift performance of the two groups trained to use different strategies would resemble those of two different developmental levels. (MP)

To clarify the roles of IQ and mental age (MA) in hypotheses behavior, MA-matched subjects at three levels of IQ and three levels of MA received blank trial discrimination learning problems using procedures designed to discourage position-oriented responding. (Author/BD)

Simple and complex learning and problem solving situations were employed with mentally retarded children and adults. In the Rotation-Discrimination Complex and the Size-Discrimination Simple experiments, upper and lower test achievement subgroups were subjected to two basic types of visual discrimination at different levels of task complexity.…

Six experiments examined the problem-solving behavior of normal and mentally retarded (MR) children with a two-choice discrimination learning situation: the effects of stimulus similarity upon types of solutions utilized by MR children; the role of redundant cues in the discrimination learning of MR subjects with differing mental ages; the…

THE CONTRIBUTIONS OF 21 AUTHORS IN THIS VOLUME ARE DEVOTED TO ASSESSING THE STATUS OF RESEARCH AND THEORY IN MENTAL DEFICIENCY, FOCUSING ATTENTION ON THE BEHAVIOR OF THE MENTALLY HANDICAPPED. PART ONE IS CONCERNED WITH RESEARCH FINDINGS AND THEORIES TO EXPLAIN MENTAL DEFICIENCY. COMPREHENSIVE PSYCHOLOGICAL THEORIES REPRESENTED INCLUDE FIELD…