Futureproof Extra: Why Do We See Ghosts?

Have you ever seen a ghost, or a UFO, or had some seemingly supernatural experience that you can’t explain? If you haven’t, we'd be willing to bet you probably know someone who has. These experiences are fairly common across cultures and they can’t all be the work of hoaxers and charlatans. So what’s going on? Chris French is Emeritus Professor of Psychology in the Anomalistic Psychology Research Unit at the Goldsmiths University of London. He joins Jonathan to discuss.