Gender differences in self-estimated IQ: The need for care in interpreting group data

This study sought to examine differences between estimated intelligence and measured IQ among males and females. Forty-six male and 80 female participants were asked to estimate their own IQ and to complete the Digit Symbol and Vocabulary tests from the WAIS. Analysis of group data revealed a significant gender difference in self-estimated IQ, with male self-estimates higher on average than those of females. Moreover, male self-estimates were found to be significantly higher overall than their measured IQs and female self-estimates were lower than measured IQ, although not significantly. Consideration of these results at individual level, however, indicated that, for the majority of subjects, the overall pattern of results for males and females was strikingly similar and that statistically significant group differences were due to a few ‘outliers’ who displayed large discrepancies between estimated and measured IQ. It was concluded that speculation about the causality of inaccurate self-estimates of IQ should not be based on the assumption that gender differences at group level represent a generalized tendency on the part of either sex to either over-confidence or lack of confidence with regard to their own intelligence.