Effects of Perinatal Testosterone on Handedness of Gerbils: Support for Part of the Geschwind–Galaburda Hypothesis

When assuming their species-typical tripodal stance, male Mongolian gerbils (Meriones unguiculatus) use their right forepaw for support more frequently than do females. This experiment determined whether, as N. Geschwind and A. M. Galaburda (1987) have proposed, the direction of such sexually dimorphic lateral asymmetry of forelimb use is affected by perinatal exposure to testosterone (TP). It was found that male gerbils injected with TP when 4 …