Spatial ability, throwing accuracy and man's hunting heritage

ATTENTION has recently been drawn1 to the indications that spatial ability—the ability to create, maintain and mentally transform a visual image1,2—has an X-linked recessive mode of inheritance in Caucasians1,3–8, with males having a proportionately greater facility1,9–12. At first glance, this result seems paradoxical in that such a presumably adaptive trait would not be expected to be transmitted on a recessive allele. If past selection pressures were exerted primarily on males, however in whom the spatial allele is co-dominant, the paradox would be resolved satisfactorily.