Also known as “ESP cards,” this is a deck of 25 card using a repeating set of five simple geometric shapes (circle, square, wavy lines) used to test for ESP. The cards were designed in the 1930s by Karl Zener, a perceptual psychologist, for use by famed parapsychologist J.B. Rhine.
Readers, please enjoy this guest blog post by Sandra Kynes, author of several books, including The Herb Gardener's Essential Guide, Plant Magic, and the new Witches' Encyclopedia of Magical Plants, among many others.
Although a few old books...