Taking Psychology with You

Extrasensory Perception: Reality or Illusion?

Eyes, ears, mouth, nose, skin: We rely on these organs for our experience of the external world. Some people, however, claim they can send and receive messages about the world without relying on the usual sensory channels, by using extrasensory perception (ESP). Reported ESP experiences involve things like telepathy, the direct communication of messages from one mind to another without the usual sensory signals, and precognition, the perception of an event that has not yet happened. How should critical thinkers respond to such claims? What questions should they ask, and what kind of evidence should they look for?

Evidence or Coincidence?

Much of the supposed evidence for ESP comes from anecdotal accounts. But people are not always reliable reporters of their own experiences. They often embellish and exaggerate, or they recall only part of what happened. They also tend to forget incidents that do not fit their beliefs, such as “premonitions” of events that fail to occur. Many ESP experiences could merely be unusual coincidences that are memorable because they are dramatic. What passes for telepathy or precognition could also be based on what a person knows or deduces through ordinary means. If Joanne's father has had two recent heart attacks, her premonition that her father will die shortly (followed, in fact, by her father's death) may not be so impressive.

The scientific way to establish a phenomenon is to produce it under controlled conditions. Unfortunately, most of the attempts to demonstrate ESP in the laboratory have been poorly designed, with inadequate precautions against fraud and improper statistical analysis (Alcock, 2011). As a result, the history of research on this subject has been one of initial enthusiasm because of apparently positive results (Bem & Honorton, 1994; Dalton et al., 1996), followed by disappointment when the results cannot be replicated (Milton & Wiseman, 1999, 2001). One researcher who tried for 30 years to establish the reality of psychic phenomena finally gave up in defeat. “I found no psychic phenomena,” she wrote, “only wishful thinking, self-deception, experimental error, and even an occasional fraud. I became a skeptic” (Blackmore, 2001).

The issue has not gone away, however. Many people really, really want to believe that ESP exists. James Randi, a famous magician who is dedicated to educating the public about psychic deception, has for years offered a million dollars to anyone who can demonstrate ESP or other paranormal powers under close observation. Many have taken up the challenge; no one has succeeded. We think Randi's money is safe.

Lessons from a Magician

Despite the lack of evidence for ESP, many people say they believe in it. Perhaps you yourself have had an experience that seemed to involve ESP, or perhaps you have seen a convincing demonstration by someone else. Surely you can trust the evidence of your own eyes. Or can you? We will answer this question with a true story, one that contains an important lesson about why it's a good idea to think critically regarding ESP.

During the 1970s, Andrew Weil (now known for his efforts to promote alternative medicine) set out to investigate the claims of a self-proclaimed psychic named Uri Geller (Weil, 1974a, 1974b). Weil, who believed in telepathy, felt that ESP might be explained by principles of modern physics, and he was receptive to Geller's claims. When he met Geller at a private gathering, he was not disappointed. Geller correctly identified a cross and a Star of David sealed inside separate envelopes. He made a stopped watch start running and made a ring sag into an oval shape, apparently without touching them. He made keys change shape. Weil came away a convert. What he had seen with his own eyes seemed impossible to deny . . . until he went to visit the Amazing Randi.

To Weil's astonishment, Randi was able to duplicate much of what Geller had done. He, too, could bend keys and guess the contents of sealed envelopes. But Randi's feats were tricks, and he was willing to show Weil exactly how they were done. Weil suddenly experienced “a sense of how strongly the mind can impose its own interpretations on perceptions; how it can see what it expects to see, but not see the unexpected.”

Weil was disillusioned—literally. Even when he knew what to look for in a trick, he could not catch the Amazing Randi doing it. Weil learned that our sense impressions of reality are not the same as reality. Our eyes, our ears, and especially our brains can play tricks on us.