Will the Real Clever Hans Please Stand Up?

The year is 1904. The spectators hold their breath in anticipation as a horse, Hans, stamps his hoof on the blackboard—on which the whole alphabet was written—in front of him, picking out the letters H, N, and A. The audience sighs in relief. Dohna—the name of the officer standing before Clever Hans and his owner Herr Wilhelm von Osten, and to whom they have been introduced earlier. Von Osten reaches out his hand to Hans to give the horse a treat. Everyone claps, but they look in bewilderment at each other as if to ask—how? Von Osten claims that he taught Hans just as any person might teach a child: Hans is instructed to “count” the number of balls by tapping his hoof—at the same time, von Osten counts out loud with him. Thus, supposedly, Hans associates the auditory signal provided by von Osten with the visual signals, and the hoof taps are a way for Hans to communicate the visual signals he perceives. Even philosopher-psychologist Carl Stumpf, who formed the Hans Commission in order to investigate the truthfulness of the phenomenon in 1904, concludes that Hans is, truly, capable of performing mathematical operations such as addition, fractions, and even square roots. Three years later, Professor Oskar Pfungst, a psychologist, studies the Orlov Trotter closely in his laboratory, and comes upon this conclusion: Clever Hans is clever, indeed, but not in the way his admirers, and even his trainer, know. Although Hans could generally answer the questions posed by people other than von Osten, the accuracy of his answers drops when the questioner was far, or completely obstructed from Hans’s view, and when the questioner did not know the answer to the question beforehand. Upon even closer investigation, Pfungst realizes that Hans derives his answers from the very subtle body language of his questioner. When Pfungst asks Hans a question, the psychologist looks down to observe the number of stamps the horse makes with his foot. When Hans arrives at

References: Bellows, A. (2007). Clever Hans the math horse. Damn Interesting. Retrieved from http://www.damninteresting.com/clever-hans-the-math-horse/ Bower, B