The Role of Vision in the Development of Abstraction Ability

Abstract

The study reported here investigated the differences in verbal and nonverbal abstraction ability of adults who became blind before age 2 and those who lost their sight after the age of 5, when their expressive language ability would have been more fully developed. No significant differences between the two groups were found in these areas, as measured by the Cognitive Test for the Blind and the Verbal sub-scale of the Wechsler Adult Intelligence Scale-Revised (WAIS-R). The finding that educational level affects the variability of scores on the WAIS-R suggests that differences in educational experiences may significantly influence individuals’ performance on standardized measures of intelligence.