This study with 12 elementary school children with mild mental retardationship found that the relation between lexical knowledge and mental age depended upon the nature of the vocabulary test. Results suggested that mental age in this population was more strongly related to knowledge of abstract relational terms than to knowledge of labels for…

Applies the confluence model to a longitudinal intact family data set. Also tests the data with simple linear models. Results suggest that the confluence model should be rejected as a useful model for these data based on principles of parsimony and predictability. (Author/AS)