In laboratory experiments, parapsychologists--those who study paranormal (literally, beyond the normal) happenings--have sometimes been astonished at psychics who seem capable of discerning the contents of sealed envelopes, influencing the roll of a die, or drawing a picture of what someone else is viewing at an unknown remote location. But other research psychologists and scientists--including 96 percent of scientists in the National Academy of Sciences--are skeptical (McConnell, 1991). If ESP is real, we would need to overturn the scientific understanding that we are creatures whose minds are tied to our physical brains and whose perceptual experiences of the world are built of sensations. Sometimes new evidence does overturn our scientific preconceptions. So let's look at some claims for ESP, and then see why scientists remain dubious.