Atleast until 1960s left handers were forced to learn to write with their right hand. I think a lot of older true left handers are being counted as right handed, hince their decreased representation in the older population. I am left handed and remember as a child my grandmother arguing with my mother not to “let me” keep using my left hand.
So, being left handed is a precursor to death? Got news for the researchers, we all gona die and I dont think the hand you favor has much to do with it.