In recent years, the magnitude, consistency, and stability across time of cognitive sex differences have been questioned. The present study examined these issues in the context of spatial abilities. A meta-analysis of 286 effect sizes from a variety of spatial ability measures was conducted. Effect sizes were partitioned by the specific test used and by a number of variables related to the experimental procedure in order to achieve homogeneity. Results showed that sex differences are significant in several tests but that some intertest differences exist. Partial support was found for the notion that the magnitude of sex differences has decreased in recent years. Finally, it was found that the age of emergence of sex differences depends on the test used. Results are discussed with regard to their implications for the study of sex differences in spatial abilities.

No abstract

No abstract

Hand preference is multidimensional with two major factors and a variable number of minor factors. In the present factor analyses of hand preference, there was no evidence to support Healey, Liederman and Geschwind's (1986) suggestion that hand preference dimensions can be distinguished on the basis of those requiring movement of the distal musculature (fingers and hand) and those requiring movement of the proximal. The first factor reported here relates to "skilled" activities. Hand preference for the use of tools and manipulation of other objects is strongly lateralized in self-professed right- and left-handers. "Less skilled" activities such as picking up objects load on a second and a third factor. Preference for picking up objects including very small ones and relatively heavy ones is much less lateralized, although there appears to be a distinction between activities that involve strength and those that do not. A fourth factor relates to the use of bats and axes, a bimanual activity.

No abstract