Correlations between self-estimated and psychometrically measured IQ

Following J. Reilly and C. Mulhern (1995), the authors examined the relationship between self-estimated and psychometrically measured IQs in men and women. In this study, 53 male and 140 female British undergraduates estimated their overall IQs. About 4 months later, they completed a spatial-intelligence (mental-rotation) test. The men estimated their scores significantly higher (120) than the women did (116) and also obtained significantly higher test scores (6.94) than the women did (4.43). There was a very modest but significant correlation between self-estimated IQ and actual IQ score (r = .16). The correlation was significant for the men (r = .27, n = 53) but not for the women (r = .09, n = 140). Removal of a small number of outliers had no significant effect on the results.