Sex Differences in Verbal and Performance IQ's of Children Undergoing Open-Heart Surgery

Boys with congenital heart defects had essentially normal Verbal and Performnance IQ9s on preoperative and postoperative tests; but girls9 Verbal IQ9s were significantly lower than those of boys, and significantly lower than girls9 own Performance IQ9s. This sex difference among congenital heart cases reverses the usual finding that girls excel on Verbal tests.