Nearly 90% of people are right-handed. But why is that? Hank Green of Sci Show explains that the answer could be evolution.

Only humans are so unevenly hand dominate, as even chimps don’t favor one hand over the other. That has left some scientist searching for a special ‘righty’ gene, but so far it hasn’t been found. 

The best hypothesis is that our brains are extremely asymmetrical, meaning the left side of the brain controls the right side of the body, and vice versa.

It only makes sense that the part of the brain where speech originates also controls the hand which language is created in physical form.