In 1911, researchers begin taking special interest in a horse owned by a German mathematician named Von Osten. The horse, aptly named Clever Hans, was reported to able to count – add, subtract, multiply and divide.
It was even suggested that Clever Hans could spell and solve problems involving musical harmony.
As mystifying and even magical as this seemed to be, it was concluded following a rigorous study, that in fact Clever Hans possessed no highly intelligent factors nor extraordinary abilities.
It was simply a case of Clever Hans performing what had become expected of him.
Two researchers, Stumpt and Pfungst, realized that when the handlers of Clever Hans posed questions to him, they were providing subtle physical and verbal cues to the horse as it pertained to the answer.
This reality was summarized in the book, ‘Teachers and the Learning Process’ written by Robert Strom (Prentice-Hall, 1971):