Doreen Kimura

The relationship between testosterone levels and cognitive ability patterns

The cognitive performance of normal men and women was studied, grouped according to whether the subjects had relatively high or low salivary testosterone (T) concentrations. Men with lower T performed better than other groups on measures of spatial/mathematical ability, tasks at which men normally excel. Women with high T scored higher than low-T women on these same measures. T concentrations did not relate significantly to scores on tests that usually favor women or that do not typically show a sex difference. These results support suggestions of a nonlinear relationship between T concentrations and spatial ability, and demonstrate some task specificity in this respect.

Sex, sexual orientation and sex hormones influence human cognitive function

Superior performance by women on a task requiring object location memory has challenged the traditional view that men excel on all spatial tasks. Sexual orientation is also associated with variation in cognitive ability pattern, but such association appears to be more consistent for a real-world targetting task than for paper-and-pencil spatial tests. Finally, there is increasing evidence that early exposure to sex hormones has lasting effects on problem-solving behaviour; moreover, current fluctuations in sex hormones in both men and women are associated with changes in cognitive pattern.

WOMEN'S ADVANTAGE ON VERBAL MEMORY IS NOT RESTRICTED TO CONCRETE WORDS

It is well established that women perform better than men on tests of verbal memory, but the nature of this advantage is unclear. To examine whether reference to a real object is a factor, we presented several verbal memory tasks, including one containing words high and low in concreteness. Over all tests there was an expected female advantage. Although concrete words were recalled much better than abstract words, the female advantage was equivalent on both. The sex difference was not accounted for by a difference in verbal intelligence. Possible brain and adaptive mechanisms are discussed.

Human sex differences in cognition, fact, not predicament

Sex differences in cognition are not trivial nor have the most salient differences declined over the last three decades. There is compelling evidence that sex hormones are a major influence in the organization, and perhaps the maintenance, of cognitive sex differences. Anatomical brain differences are also well established, though we have yet to associate these firmly with the cognitive sex differences. While it is reasonable to question the specifics of the traditional hunter-gatherer evolutionary schema, it is argued that it remains valuable in providing a paradigm for understanding human sex-differentiated behaviour, since it is capable of generating hypotheses that can be tested.