Researchers studying 30,000 year old cave art left behind by our ancestors have made an interesting observation – that the proportion of left handers amongst the artists is the same as it is today – just over 20%. Charlotte Faurie and Michel Raymond and the University of Montpellier studied over 500 hand prints left on the walls of 26 caves in France and Spain. The prints were made by blowing paint from a pipe at a hand pressed against the cave wall. 25% of the impressions were of a right hand, indicating that the artist must have used their left hand to steady and aim the blowpipe. Left handedness seems to have a genetic basis [compared with a child born to right handed parents, a child born to one left handed parent is about 2x as likely to be left handed, and 2.75x as likely if both parents are left handed] but we still don’t understand why left handedness has remained so common and so stable for such a long time. One suggestion is that because left handedness is uncommon it gives individuals advantages over right-handers under certain situations like fighting.