Spearman's hypothesis states that the differences between Blacks and Whites in psychometric IQ are attributable to a fundamental difference in general intelligence ("g"). To investigate this hypothesis, Jensen devised the method of correlated vectors. This method involves calculating the correlation between the factor loadings of the…

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…

This study investigated the effects of classroom composition on achievement. The analysis focused on the assessment of classroom homogeneity with respect to the socioeconomic background and general intelligence of the students. In addition, the extent to which classroom composition affects the standards the teachers employ and how these standards…