Summary.A stratified sample of 160 fourth and fifth‐year secondary school pupils, all of whom had completed a mathematics course leading to the Certificate of Secondary Education, were given a series of mathematics tests. These tests were structured into four sections according to item type, multiple‐choice, data sufficiency, multi‐facet and traditional, each section being divided into two broad content areas, number and space. A six‐way analysis of variance of the scores, separating the main and interactive effects of extraversion, neuroticism, ability, sex, item type and content area, showed that: (i) extra‐verted boys and introverted girls constitute a higher performing group within their own sex; (ii) the overall performance of both stable introverts and neurotic extraverts stands out in relation to that of the other personality types; (iii) among those of high ability introverts do better, while among those of lower ability extraverts do better; and (iv) stable pupils do better than the neurotic on traditional items in space content, this being the only significant difference in a directly opposite pattern of neurotic‐stable differences in the two content areas.It is suggested that introversion might become advantageous at an earlier age for girls than for boys, and that all future studies in the field should take account of both the form and content of the assessmen