Dual asymmetries in handedness
Jones GV., Martin M.
The possibility that two forms of asymmetry underlie handedness is considered. Corballis has proposed that right-handedness developed when gesture encountered lateralized vocalization but may have been superimposed on a preexisting two-thirds dominance. Evidence is reviewed here which suggests that the baseline asymmetry is even more substantial than this, with possible implications for brain anatomy and genetic theories of handedness.