Children blinded from retinoblastoma, and who were at blind school, were of either average or above average intelligence, the number above average exceeding the number ofaverage intelligence when tested on the Williams Intelligence Test Scale. A group of children blinded from causes other than retinoblastoma were also tested, and it was shown that the retinoblastoma children had a significantly higher IQ. A group of sighted children from four normal schools were tested on the same Test Scale; the retinoblastoma children scored 17 points of IQ higher than the sighted children. A search for some explanation that might account for the superiority of the retinoblastoma children in respect of intelligence led to no wholly satisfactory hypothesis.
