Impulsivity-Reflectivity and Cognitive Development in Preschoolers: A Longitudinal Analysis of Developmental and Trait Variance

Because impulsivity-reflectivity (IR), as measured by the Matching Familiar Figures Test (MFF; Kagan, 1965) and KRISP (Wright, Note 1), is correlated with age and IQ, we sought to determine how much variance in impulsivity-reflectivity is attributable to an impulsivity-reflectivity trait and how much to cognitive development, as measured by mental age (MA). Since the usefulness of measures of impulsivity-reflectivity depends upon whether they pred ic t b e h a v i o r n o t p r e d i c t a b l e f r o m developmental level, we included a test of hypothesis behavior, which Kagan (cf. Kagan & Kogan, 1970) believes is central to stylistic differences in cognitive processes. Fifty-five boys and 47 girls in nursery and daycare settings were tested twice, at a mean interval of 6.0 months; 76 were white and 26 nonwhite. The Stanford-Binet short form was administered at each testing according to an optimizing procedure whereby easy items were alternated with difficult items. At Testing 1, mean chronological age was 50.0 months, mental age 57.3, IQ 103.8, and Hollingshead (Note 2) socioeconomic score 3.0, in which 1 is the highest and 7 the lowest parental occupation. At both testings, a measure of impulsivity-reflectivity and, at Testing 2, a measure of hypothesis usage followed the Stanford-Binet within 3 days. The impulsivity-reflectivity measure was a modification of the KRISP designed to obtain enough variance in impulsivity-reflectivity for a valid test of the target relationships. It comprised six items from Form A and six from Form B of the KRISP, Item 1 of MFF Set 1-F, and an item drawn for this study. The remaining KRISP items were omitted because pilot work showed few errors on them.