Joe Hanson is a biologist and the host of the PBS online series It’s Okay to Be Smart. In this video, he explains why it’s odd that there so few left-handed people. It’s a mystery because other animals do not possess this characteristic. The odds of a dog favoring a left or right forepaw are about 50/50.
Scientists have not been able to determine with certainty why there are so few left-handed people, but they have a few theories. One is that early hominids possessed a genetic mutation encouraging right-handedness. Left-handed people aren’t people with a left-handedness gene, but people who lack the right-handedness gene. You can learn more about this theory and others in the video above.