Why are most people right-handed?

Our brain determines our handedness. The left side of the body is controlled by the right hemisphere of the brain and the right side of the body is controlled by the left hemisphere of the brain. Right-handers are left-hemisphere dominant while left-handers are right-hemisphere dominant. About 88 per cent of humans are right-handed and the rest are left handed. A truly ambidextrous person - one who is equally hemisphere dominant and who equally uses either hand - is quite rare. According to science writer Marc McCutcheon, "Most cases of left-handedness are thought to be caused by minor brain damage before or during birth. Many scientists believe the damage is due to reduced oxygen supply before birth." Twins have a higher than usual rate of left-handedness. This is believed to be caused by twins having to share less space in utero and perhaps receiving less oxygen. 65% of those suffering from autism are left-handed. Left-handedness is found to be more common than usual among the world's artists and also among the world's gays.

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