The Sheep-Goat Effect is a term coined by Gertrude Schmeidler, a professor of psychology at the City University of New York, in 1942. It is used in parapsychology to describe the influence of a person's belief in the paranormal on their performance in psychic experiments.

Schmeidler categorised those who believe in paranormal phenomena as "sheep," while "goats" are skeptics. Studies suggest that believers tend to score higher on tests of psychic ability than non-believers, indicating that belief may impact one's openness to or ability to experience paranormal events.

The researcher asked her volunteers to attempt to identify the image on the faces of a deck of concealed Zener cards. The cards have five different images on them: a cross, a square, a circle, a triangle, wavy lines, and a star. There are 25 cards in a deck. So if you picked at random, you'd expect to get one in five right on...