WISC and WAIS IQS as a Function of Season of Birth

Abstract

WISC and WAIS Verbal, Performance and Full Scale IQs of Ss born during Summer-Autumn (May through October) and Winter-Spring (November through April) were compared. The results suggested some possible seasonal effects evidenced on the WISC Verbal IQ, and WAIS Performance and Full Scale IQs and perhaps the WAIS Verbal IQ. Inadequate controls and possible contaminating factors in the study were indicated. Adequately controlled studies must be performed to determine whether seasonal effects of birth exist, prior to further speculation.