Beginning in 1891, crowds throughout Europe were spellbound by the amazing feats of the horse Clever Hans. Urged on by his owner William Von Osten, Clever Hans would answer questions by tapping a hoof on the ground. For example, 5 and 9 were once written on a blackboard and he was asked to add them together. Clever Hans proceeded to tap his hoof 14 times. What was his secret?
The Secret of Clever Hans?
It took 16 years but finally, a philosophy professor named Carl Stumpf and his student Oskar Pfungst solved the mystery. It turned out that Clever Hans based his responses on “unconscious cues” provided by Von Osten. In other words, when Clever Hans reached the correct number of hoof taps, Von Osten would unknowingly change facial expressions or lean forward. Clever Hans would stop and then receive a reward for his “guess,” which served to reinforce the behavior.
Incidentally, this is a primary reason that modern psychologists use double-blind experiments or communicate with subjects via computers. Here’s more on Clever Hans from Benjamin Radford at Discovery News:
You may think your dog or cat is smart and amazing, but it’s got nothing on a horse that drew huge crowds in Germany and throughout Europe over a century ago.
The horse, named Clever Hans, was known around the world for his inexplicable abilities. William Von Osten put his amazing horse on display in 1891, and together he and Hans treated crowds to sights never before seen.
Not only could Hans count — something no other animals were said to do — but he could also tell time, read, and spell (in German, of course).