I don't know if it answers your question, but this related fact might tell something.

Most people are right handed. The custom of shaking hands with the right hand was because if you were using your dominant hand you could stab a person while shaking hands. A left handed person could; however, could shake hands and stab with a knife or sword. That would be kind of "sinister".

Since most people are right handed, they are more dexterous with their right hand.