It may also have a little to do with the fact that when you have a stroke or heart attack, the first pains are usually in your left side. I don't know why, it just is. Right brained people (i.e., left handed) recover motor function more often and better than left brained (i.e., right handed) people after a stroke or heart attack. If you were superstitious enough to believe you had a good and evil spirit, would it not be logical to connect the evil spirit with the pains of a stroke? Thus making the left side, as the first to be affected, the side where the evil spirit is grabbing you.

I'm at least 3rd generation left handed, and my daughter is the 4th generation. And very proud of being so.

LTS