A reanalysis of B. Inhelder's (1968) data concerning cognitive development among retardates was performed by selecting from the original 159 subjects a sample of 104 educable mentally retarded Ss (7-19 years old) who were diagnosed as fixated or nonfixated at three of the cognitive stages postulated by Jean Piaget. The results indicated that among…

This report discusses the outcomes of a study that examined 216 comparably aged children and adolescents (ages 2-18) with fragile X or autism to determine whether longitudinal change in cognitive ability and adaptive behavior was similar in the two groups. Results found decreases in Intelligence Quotient scores in young children with fragile X as…

The perceptions of parents of 113 developmentally delayed preschool children were compared with mental ages derived from the Cattell Infant Intelligence Scale and the Stanford Binet Intelligence Scale. With the parents as informants, an Alpern-Boll Developmental Profile was completed. Findings demonstrated a high degree of correlation between the…

To learn if differences in age, intelligence, and sex account for differences in children's memory of TV commercials and "degree of insistence" (DI) after viewing them, 54 gifted, 71 normal, and 53 educable mentally retarded children (of both sexes, 7-13 years) were questioned. The mediating influence of the three independent variables on DI was…

The purpose of this study was to investigate further the relationship between sex and a decline of intellectual abilities during adolescence and to examine some personality differences between young women who declined in intellectual abilities during adolescence and those who did not. Differences examined were: need to be included, need to be…

The cognitive determinants of number series completion performance were studied by presenting a systematic set of problems to adults and to children of high and average intelligence, grades 4 and 5. Pearson correlations between these problems and the number series on the Cognitive Abilities Test were .51, .78 and .43 for the average intelligence,…

The expert-novice paradigm, which demonstrates the outstanding role of domain-specific knowledge in explaining differences in memory behavior and performance, was examined. Two studies are described which compared memory performance of groups equivalent with regard to domain-specific knowledge but differing in intellectual ability. The hypothesis…

This paper discusses research exploring the performance factors involved in studies which test for formal operations. It is suggested that several previous studies dealing with formal operations confound performance and competence in determining the extent of subjects' formal operations schemata. Factors which might account for performance…

This paper reviews studies in which scores on Piagetian tests of logical thought were correlated with IQ, mental age (MA) and chronological age (CA), and examines the possible effects of the size of the age range and mean age of subjects on these correlations. The data included 44 groups of subjects obtained from 36 studies in which Piagetian and…

A prospective longitudinal investigation related 76 maternal and infant variables to performance on the Metropolitan Readiness Tests (MRT) at age six. The 1,245 study subjects have been followed since birth. Their distribution on measures of intelligence and socioeconomic status is essentially normal. Subjects with high MRT scores were found to…

The cognitive determinants of number analogy performance were studied by systematically manipulating the processing demands imposed by the items. To explore sources of developmental differences in analogical reasoning, subjects were included from two age levels, grades 4 and 5 and college. To allow the investigation of individual differences in…

This study investigates the effect of curiosity in first and second grade children as an individual difference variable in learning in a computer-based interactive learner control environment and discusses the implications for instructional designers and educators. The instruction was an art education lesson containing both facts and concepts. The…

This study focuses on the effects of family size and spacing on intellectual, social, and personality development of children. The sample consisted of 533 suburban, middle class, large family (five or more) and small two child family children. The children, 233 boys and 300 girls, were teenagers attending either junior or senior high school.…