• When you cross your legs, which one goes on top? In 62 percent of the population, the right leg is the top one, while 26 percent cross with their left on top, and 12 percent go either way.



• The percentage of left-handed people is pretty constant around the world, but there are some regional variations. For example, Dorothy Bishop (a scientist who is well known for her work on language and handedness) reported in 1990 that 17 to 22 percent of the Kwakiutl Indians of British Columbia were left-handed, the highest number she was aware of in any group. No culture is known in which there are equal numbers of left- and right-handed people, a strong argument that the cause of handedness is biological, not cultural.



• People generally chew with one side of their mouth more than the other. As you might guess, one study suggests that right-handers tend to be right chewers as well.



• If you are right-handed, are you also likely to be right-faced? Well, no, not really. Although one side of the face does tend to move more than the other when expressing emotions, "facedness" seems to be related to "eyedness," but not to handedness.



• Men are slightly more likely than women to be left-handed. No one knows why, but a popular theory suggests that it has to do with an effect of testosterone on the developing brain.



• In a small study of children age 12 to 18 months who used sign language, 82 percent signed right-handed, according to their parents. Adult sign language users who have left-sided brain injuries, affecting the language area of their brain, lose the ability to sign meaningfully, although they can still use their hands for other activities.



• Left-handedness seems to be somewhat less common among people over 50. Is that because more of them grew up at a time when left-handedness was not tolerated, or because left-handed people tend to die younger (this, at least, is probably not true), or because the rate of left-handedness is really going up (although no such trend has been noted among people younger than 50)? It seems unlikely that people grow out of their left-handedness after age 50. The answer? Unknown.

• Left-handed Thinking


• Questions about Handedness


• Handedness and the Brain

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