Two hundred and one adults completed two questionnaires: the first estimating their scores and that of their partner on nine scales from the General Aptitude Test Battery (GATB); the second on beliefs about IQ tests. There was overall no sex difference between participants on self-
and partner- ratings though there was an expected difference on numerical ability. Factor analysis revealed two factors labeled cognitive ability and dexterity. Regressing the eight specific abilities onto the overall score showed five abilities with significant beta weights
(particularly verbal and numerical abilities) accounting for nearly three-quarters of the variance. Regressing seven demographic factors onto the overall score showed the participants' wealth, education and political beliefs to be the best predictors: richer, longer educated, more right-wing
people thought they had higher IQ scores.