Intelligence test scores were obtained from parents and children in 300 adoptive families and compared with similar data available from the children's biological mothers. Results support the hypothesis that genetic variability is an important influence in the development of individual differences in intelligence. (Author/RH)

Proposes a theory of development in which experience is directed by genotypes and in which genotypic differences affect phenotypic differences, both directly and through experience, via three kinds of genotype-environment effects. The theory adapts the three kinds of genotype-environment correlations in a developmental model used to explain…

Tested differences in values between 60 managers and 51 organizational development consultants, using the Management Values Inventory (MVI). Results revealed that the differences between the two groups were modest, even when statistically significant. Often-stated differences between these groups were not present on the MVI. (Author/WAS)

Examines the relationship between young children's spatial exploration and their cognitive representations of environments. Children ages 20-28 months and 36-44 months explored a museum room; measures of the quantity and mode (active versus passive) of their exploration were recorded. Results indicate individual differences in the extent to which…

The kinds of individual differences in perceptions permitted by the weighted euclidean model for multidimensional scaling are more restrictive than those allowed by models developed by Tucker or Carroll. It is shown how problems which occur when using the more general models can be removed. (Author/JKS)