Are IQ discrepancies between SES groups primarily the result of Verbal Scale differences?

摘要

Historically, comparison groups of children from low socioeconomic status (SES) have done less well on intelligence tests than their more well-to-do counterparts. This study was undertaken to explore the contribution of verbal ability to general intelligence and to consider the possibility of developmental change in the relative contributions of the verbal and performance scales. The analyses used verbal, performance, and full scale scores of a subgroup of the standardization sample of the Wechsler Intelligence Scale for Children - Third Edition (WISC-III). The scores used were attained by children in three age groups (7, 11, and 15 years) with four levels of SES as determined by parental educational level. It was found that the age of the children and the interaction of age with parental education level were not significant factors. The factor of parental education level did reveal significant differences between the groups on all three measures.; Follow up analyses within the groups demonstrated no significant differences in the verbal, performance, and full scale scores of children whose parents had attained 12 to 15 years of education. For children whose parents either failed to complete high school, or those whose parents had completed college, there exists a significant difference between their verbal and performance scale scores and between their performance and full scale scores. The verbal and full scale scores of these groups do not evidence such a discrepancy. Those whose parents failed to complete high school attained verbal and full scale scores that were lower than their performance scale scores. The pattern is reversed for children of parents receiving 16 or more years of education.; Contrary to expectations, children grouped by parent education level were found to differ on all three scales. However, for the lowest and highest groups the verbal scale was more closely associated with the full scale score. While IQ discrepancies between SES groups are not primarily the result of verbal scale differences, the verbal scale is a significant factor in the scores of the highest and lowest SES groups.