This longitudinal randomized-control trial investigated the effectiveness of scientifically based reading instruction for students with IQs ranging from 40 to 80, including students with intellectual disability (ID). Students were randomly assigned into treatment (n = 76) and contrast (n = 65) groups. Students in the treatment group received…

Examined major discriminating factors for cognitive development in high-IQ and low-IQ children in child care who had been adopted after age four. Found that birth rank, maternal mental retardation, pregnancy/delivery complications, severe prematurity or low birthweight, and number of hospitalizations differentiated the two groups. Over time, IQs…

Confluence theory was developed to explain the negative effects of birth order on intelligence. Using aggregate, between-family, within-family, and paired-sibling data from the Wisconsin Longitudinal Study, tests the mathematical form of confluence theory and finds no support for it. Suggests that statistical methods used to fit the model to the…

In an effort to isolate the emergence and causes of social class differences in intellectual performance, this longitudinal study was undertaken as a follow-up on a cross-sectional study that yielded no social class differences on the Cattell Infant Intelligence Scale for 12-, 18-, and 24-month-old black children. In the present study, 89 children…

This book is organized in nine parts, as follows. Part I, "Preface," includes an account of how the author went from the rather esoteric research on theoretical problems in serial rote learning to research on the inheritance of mental abilities and its implications for education. Part II, "How Much Can We Boost IQ and Scholastic Achievement?," is…

Investigated the change in IQ scores over time of subjects in classes for the Educable Mentally Handicapped. Analysis indicated a significant difference existed between Wechsler Intelligence Scale for Children scores administered at initial placement and Wechsler Adult Intelligence Scale scores administered later (mean age, 17 years-6 months).…

Scores on the Wechsler Adult Intelligence Scale (WAIS) were compared with reevaluation scores obtained four years later on the WAIS-Revised for a group of 108 mildly and moderately retarded adults. The moderately retarded subgroups (N=22) demonstrated significantly higher WAIS-R intelligence quotients. Implications for use of the WAIS-R are…

Critically reviews the influential study "Malnutrition and Environmental Enrichment" by Winick et al. (1975) and highlights what are considered to be statistical flaws in its analysis. Data in the classic study of height, weight, and IQ changes in three groups of adopted, malnourished Korean girls are reanalysed and conclusions…

Swedish longitudinal studies of twins support Scarr-Salapatek's explanation of nature-nurture influences on intelligence. This model predicts more genetic variance in test results for advantaged than disadvantaged groups. Jensen's work, however, suggests equal amounts of variance among different social classes. (Author/CP)

IN THE LONGITUDINAL BERKELEY GROWTH STUDY, SUBJECTS WERE TESTED AT 16, 18, 21, AND 26 YEARS ON THE WECHSLER-BELLEVUE, AND AT 36 YEARS ON THE WECHSLER ADULT INTELLIGENCE SCALE, WHICH CONTAIN BOTH VERBAL AND NON-VERBAL SUBSCALES. THE MOST CONSISTENT INCREASES IN MEAN SCORES OVER THE PERIOD WERE IN INFORMATION, VOCABULARY, AND COMPREHENSION. DIGIT…