Parents and their teenage children (N=104 families) were administered a battery of paper and pencil tests containing measures of English vocabulary, letter concepts, spelling, metal arithmetic, and identical blocks. After standardization of the results to correct for age, children scoring on any test 1 SD above or below the mean were identified and their parents compared to see whether the mother or father was the higher-scoring partner. Low-scoring children were found to have mothers scoring higher than fathers only 23% of the time, while high-scoring children had mothers exceeding their husbands 44% of the time. These results were interpreted as suggesting the presence of a maternal effect on intellectual functioning.