Several meta-analyses have shown that males outperform females in overall spatial ability, while females outperform males in some verbal ability tests, but not in others. The present article measures sex differences in two computerized tests, one thought to reflect verbal reasoning and one thought to reflect dynamic spatial performance. The sample comprised 1,593 university graduates (794 females and 799 males). Results show that males outperform females in both tests. However, sex differences in verbal reasoning turn to be nonsignificant when sex differences in dynamic spatial performance are statistically removed. The finding is interpreted from the previously demonstrated fact that the verbal reasoning test requires spatial processing. The result raises doubts about the common practice of evaluating sex differences in cognitive abilities from the tests' superficial characteristics or information content. The interpretation of the observed findings strongly requires the analysis of the tests' cognitive requirements.