• The measured IQ and parental educational level of 57 children with Down's syndrome were compared. The phenomenon of decreasing IQ with increasing chronological age in Down's syndrome was considered in the data analysis. There was no trend toward better cognitive performance by children of higher-educated parents. Thirty-one of the children had attended an early, continuous stimulation program. This experience accounted for most of the observed IQ variance.
(Am J Dis Child 133:700-703, 1979)