Question: Is it true that the right side of your brain controls the left side of your body, and that the left side of your brain controls the right side of your body? If so, why is it like this?

Rebecca Dewey answered on 15 Jun 2015:

On the whole, yes this is true. We’re not entirely sure why this happened, but in the case of movement, it may be influenced by balance. When your balance is off on the left side of the body, this needs to be corrected by moving the right side of the body, and vice versa. There are also theories about how it helps the brain to turn information coming through the eyes more easily into pictures and form a full 3D image of the world in front of us. However, not all parts of the brain truly control the opposite side of the body. For example, the sound information from the ears is usually processed by both sides of the brain. Some things are done more in one side than the other, for example, language is mostly processed in the left side of the brain, and understanding spatial movement (where a sound or image is moving from/to) is often thought to be processed in the right side.