(From Silverman & Eals [1992]. Sex differences in spatial abilities: Evolutionary theory and data. In J. Barkow et al. [Eds.], The adapted mind: Evolutionary psychology and the generation of culture. New York: Oxford University Press.) Silverman and Eals (1992) were interested in exploring sex differences in spatial ability. A number of studies show that males perform better than females on tasks of spatial orientation (ability to perform mental transformations necessary to maintain accurate orientations during movement). Based on a theory about sexual division of labor in evolutionary history, Silverman and Eals (1992) proposed that females may perform better on tasks of spatial memory (ability to recall the location of objects in space). In one test, 20 women and 21 men were placed in a room in which there were a number of objects. Later, they were asked to recall the objects in the room and where they were. Women correctly recalled an average of 11.55 items (S = 5.23). Men correctly recalled 6.80 items (S = 4.34).

Comparison distribution df =

Comparison distribution m Difference =

Comparison distribution S Difference (Give at least 3 places past the decimal point) =

Critical Value(s) using = .01 Give 3 places past the decimal point)