Sheep-goat effect

The sheep-goat effect is a term coined by Gertrude Schmeidler to describe an apparent phenomenon in psi research. "Sheep" were first defined as "those who think ESP is possible under a given experimental condition" and later redefined as "those who believe ESP exists as a genuine phenomenon". "Goats" were the opposite, those who didn't think it was possible or didn't believe in ESP. The sheep-goat effect was the observation that sheep tended to perform well in psi tasks while goats tended to perform poorly.