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…

Children and adolescents who had positive Dye Tests for toxoplasmosis had lower performances on all verbal subtests than those with negative Dye Tests. The impairment was comparable to subjects with brain damage. Subjects with congenital sight deficiency and positive Dye Tests showed progressive intellectual impairments. (Author/CM)