Designed by Dr. Karl Zener during the 1930s for psychologist J.B. Rhine, Zener cards are used to test the Extrasensory Perception (ESP) ability known as Telepathy.

Each card has one of five symbols on one side: a circle, a square, a star, a “plus sign,” and three wavy lines grouped tightly together. At the beginning of the test, the twenty-five cards in the pack are shuffled, and the tester picks up the top card and concentrates on its symbol while keeping this image hidden from the test subject.

The subject is then asked to identify the image that the tester is seeing. According to ESP researchers, if the subject is indeed telepathic—that is, able to “receive” an image transmitted by a “sender”—he or she will give the right answer significantly more often than 20 percent of the time (more than one in five times), the success rate dictated by the laws of probability.

Some people are indeed able to do this, but skeptics attribute higher success rates to cheating (and indeed, some of the first Zener cards were inadvertently made thin enough to see through) or to the subject’s ability—conscious or unconscious—to pick up unintentional clues given by the tester.

SEE ALSO: extrasensory perception, Rhine, J.B.; telepathy

SOURCE:

The Greenhaven Encyclopedia of Paranormal Phenomena – written by Patricia D. Netzley © 2006 Gale, a part of Cengage Learning