Visuospatial/vocabulary differences in boys and girls and a potential age-dependent drift in vocabulary proficiency

A total of 188 monolingual (English) boys and girls whose ages ranged from 6 years through 14 years were administered the Vocabulary and Block Design subtests of the Wechsler Intelligence Scale for Children. Although the boys (n = 85) displayed significantly greater relative strengths for the visuospatial task than the girls (n = 103), the effect was due primarily to the boys' less proficient Vocabulary scores. The detection of a significant linear decrease (r = -.32) in standardized scores for Vocabulary but not for Block Design over this age span was not expected. The drift over 9 grades was equivalent to more than one standard deviation. Possible sources of interference such as exposure to the same second language that occupied 6% to 12% of the instructional time are suggested.