Using data from a broader longitudinal study, this investigation explores within-subject and cross-generational stability of intellectual competence and the relationship of such stability to aggressive behavior. Data were gathered three times (when subjects' modal age was 8, 19, and 30 years). Initially, subjects included the entire population…

Estimates confluence model of intellectual development for a within-family sample of 321 children from 101 transracial adoptive families. Mental ages of children and their parents and birth or adoption intervals were used in a nonlinear least-squares estimation procedure to obtain children's predicted mental ages. Results suggest efficiency of the…

Explains that from a prediction standpoint the confluence model is not very efficient. Very modest increments in accuracy are associated with family configuration variables once chronological age is covaried. Suggests that the major postulates of the theory be tested directly, within individuals and with longitudinal data. (Author/AS)