Support for the confluence model of intellectual development has come from analyses of family size-birth order means of large aggregate data sets. Analyses of individual scores do not substantiate the confluence model, as explained variance is markedly reduced. The study of family interaction variables utilizing longitudinal data is recommended.…

Separate dimensions of infant cognition were compared with parental general- and specific-cognitive abilities for 182 adoptive and 164 nonadoptive families. More parent-offspring resemblance was present when 24- rather than 12-month Bayley factors were used. Bayley factors were more related to parental g than to specific abilities. (Author/RD)

Assessments of the home environments of 116 families whose twins were participants in a longitudinal study of early mental development were conducted. Predictions of offspring intelligence scores increased from ages six months to six years old. Although home/family variables were related to mental development, so were parental education and SES.…