Retinoblastoma and superior verbal IQ scores?

Abstract

Experienced teachers have long asserted that children blind from retinoblastoma (Rb), a rare cancer of the eye, are of above average intelligence. To test this hypothesis, standardized verbal intelligence tests were administered to a sample of 85 children and adults, all diagnosed with the early infancy form of this condition. For 42 of the Rb participants, a control group was assembled of other blind individuals, each matched one-to-one on age, age of onset of the blindness, duration of the condition, sex, and educational history/background. The IQ scores of 200 visually impaired children are also presented for general comparison purposes in view of a common belief that verbal ability may be enhanced when sight is impaired. The mean verbal IQ of the 85 Rb participants was significantly above that of the sighted population upon which the IQ tests had been standardized. Also, the mean IQ of the sub-group of 42 Rb participants was statistically significantly superior to that of their 42 matched control group peers.