41. Cardon, L. R., & Fulker, D. W. (1994). A model of developmental change in hierarchical phenotypes with application to specific cognitive abilities. Behavior Genetics, 24, 1-16.

This model combines multivariate and longitudinal methodologies for assessment of continuity and change in the relationships among characters over time. The model also permits assessment of shared and independent groups of measures. The procedure is illustrated by application to specific cognitive ability data from adopted and nonadopted siblings and monozygotic and dizygotic twin pairs. The results suggest that much of the observed continuity in general intelligence measures is due to genetic influences common to specific abilities and indicate different causes for specific abilities at different times in childhood.