Sources of continuity among nine measures of infant cognitive processing and later childhood intelligence quotient were examined through developmental structural equation models applied to a sample of 208 twin pairs measured from 7 to 36 months. Skills assessed appear related to general cognitive ability in a relatively unstable manner. (SLD)

Data from the Colorado Adoption Project for 493 first-grade adopted and nonadopted children are used to separate parental intelligence quotient (IQ) from the effects of school environment. Several of the variables show direct environmental associations with reading and mathematics achievement independent of effects of parental IQ. (SLD)