https://www.youtube.com/watch?v=-D4faeEb06o

Prefer one hand to another
Take another look at those hands of yours. You have two of them, correct? Then why is it that you tend to use just one of these appendages for so many tasks?

Whether you're a leftie or a righty, the fact that you have a dominant hand at all is a bit weird, according to scientists. After all, having two hands with excellent motor skills would be a real boon for humans.

One theory about why people have dominant hands has to do with the way the brain processes speech. The theory holds that the left brain hemisphere — where the speech center of most humans resides — is more intricately wired than the right brain hemisphere. The left brain hemisphere also happens to control the right side of the body. It's possible that the extra wiring in this part of the brain is behind the dominance of the right side of the body in right-handed people.

However, researchers have found that not all righties have speech centers residing in the left brain hemisphere. In other words, this theory might not be correct. However, there are lots of other theories that could help ....https://www.livescience.com/17....009-left-handedness-