Sex Differences In Mental Ability Research Articles

Sex differences in mental ability: A proposed means to link them to brain structure and function

Recent work with the 42 mental ability tests administered to participants of the Minnesota Study of Twins Reared Apart (MISTRA) has suggested that there are important dimensions of mental ability that function independently of g. Two of these dimensions, rotation–verbal and focus–diffusion, appear to involve trade-offs: greater residual rotation ability implies less residual verbal ability and vice-versa, and the focus–diffusion dimension functions similarly. These two uncorrelated dimensions also show strong sex differences. Individuals lying at different positions along these dimensions may have brains that differ structurally and/or functionally, leading to differences in the ways they approach mental ability tasks. If so, we should expect a lack of factorial invariance in test scores across groups of individuals lying at different positions on the two dimensions, indicating that the tests do not measure the same constructs in the same ways in the different groups. This study demonstrated such a lack of factorial invariance in each of the three mental ability batteries included in the MISTRA assessment. The Wechsler Adult Intelligence Scale can be scored to correlate .7 with each of the two dimensions. We propose that use of these scores may help to clarify brain-mapping studies relating brain structure and function and to facilitate understanding of sex differences in mental abilities.

Sex differences in mental abilities: g masks the dimensions on which they lie

Empirical data suggest that there is at most a very small sex difference in general mental ability, but men clearly perform better on visuospatial tasks while women clearly perform better on tests of verbal usage and perceptual speed. In this study, we integrated these overall findings with predictions based on the Verbal–Perceptual–Rotation (VPR) model ([Johnson, W., and Bouchard, T. J. (2005a). Constructive replication of the visual–perceptual–image rotation (VPR) model in Thurstone's (1941) battery of 60 tests of mental ability. Intelligence, 33, 417–430.; Johnson, W., and Bouchard, T. J. (2005b). The structure of human intelligence: It's verbal, perceptual, and image rotation (VPR), not fluid and crystallized. Intelligence, 33. 393–416.]) of the structure of mental abilities. We examined the structure of abilities after removing the effects of general intelligence, identifying three underlying dimensions termed rotation–verbal, focus–diffusion, and memory. Substantial sex differences appeared to lie along all three dimensions, with men more likely to be positioned towards the rotation and focus poles of those dimensions, and women displaying generally greater memory. At the level of specific ability tests, there were greater sex differences in residual than full test scores, providing evidence that general intelligence serves as an all-purpose problem solving ability that masks sex differences in more specialized abilities. The residual ability factors we identified showed strong genetic influences comparable to those for full abilities, indicating that the residual abilities have some basis in brain structure and function.

Sex differences in mental abilities, hemispheric lateralization, and rate of physical growth at adolescence.

Sex differences in mental abilities, hemispheric lateralization, and rate of physical growth at adolescence.

Sex differences in mental abilities, hemispheric lateralization, and rate of physical growth at adolescence.

Sex differences in mental abilities, hemispheric lateralization, and rate of physical growth at adolescence.

Sex differences in cognition: a function of maturation rate?

Regardless of sex, early maturing adolescents performed better on tests of verbal than spatial abilities, the late maturing ones showed the opposite pattern. Those maturing late were more lateralized for speech than those maturing early. Sex differences in mental abilities, it is argued, reflect differences in the organization of cortical function that are related to differential rates of physical maturation.

A Study of Sex Differences in Intelligence-Test Scores Among 1,306 Negro College Freshmen

The belief in hereditary sex differences in mental ability is an old and persistent one; but among scientists, sex as a cause of differences in intellectual equipment appears to be relatively unimportant. In the general public, however, the belief still prevails, as manifested by the reluctance to open certain educational and professional opportunities to women and by the frequent discrimination against individuals on the basis of sex alone. Experimental studies of sex differthose dealing with the separate parts or specific items of tests of intelligence; and '(3) those dealing with achievement in the several school subjects as revealed by objective educational tests. The results have yielded largely negative conclusions. When large unselected groups are used, when age is taken into account, when possibilities of bias in test content are allowed for, startling differences between the sexes either in average tendency or in variation fail to emerge. It should be noted, however, that this conclusion is re-

Sex differences in mental ability among junior high school pupils.

Sex differences in mental ability among junior high school pupils.