Clever Hans: It’s Not About the Horse

In the September 24, 1904 edition of Scientific American, an article titled “A Reasoning Horse,” leant legitimacy to the idea that Clever Hans, a stallion, had the ability to count, solve simple arithmetical equations, convert common fractions into decimal fractions, and the like. The article, to say the least, was thin on skepticism.

The short, more accurate, version of the “Clever Hans” story is that Wilhelm Von Osten trained his stallion to “count” by using cues that were both conscious and non-conscious on his part, followed by a pleasurable reward, usually in the form of food and positive attention. As most of these stories go, the newspapers pitted the heroes (Von Osten and “der kluge Hans”) against the villains (the skeptics who accused Von Osten of “ingeniously concealed trickery”). And, because the cuing was so subtle and unexpected, it took the skeptics longer to prove their case than it did for the belief in the horse’s intelligence to take hold in the imaginations of people who really wanted the story to be true.

I don’t necessarily believe Von Osten’s behavior was the result of ingeniously concealed trickery. At least, not at first. What I think happened is that Von Osten probably did consciously set out to teach his horses (there were at least two) some conjuring tricks as typically seen in circus and carnival acts with horses, dogs, monkeys, elephants, etc., and then started to make claims that to him probably seemed “real,” but were the result of motivated reasoning or self-deception. That he found “experts” to back up his claims only added to the mythos around the event. It didn’t help that these experts weren’t necessarily trained in horse behavior, the techniques used by animal trainers, or in language and literacy acquisition, but instead focused solely on the horse’s written output as proof of intelligence.  They may have been sincere in their efforts, but nevertheless failed to consider the trainer’s behavior in the success of the communications, which we now know played a significant role in the horse’s ability to count. Von Osten’s (human) failing was that he focused only on the “successful” sessions that to him proved the horse’s intelligence, and downplayed, rationalized away, or ignored the failed instances of problem solving.

A second Scientific American article published in November 12, 1904, “The Uncleverness of ‘Clever Hans,’” called into question some of the horse’s responses. Had Von Osten made any attempts to responsibly address these issues, history may have looked on him more favorably. The scientific process isn’t about straying off the path occasionally in pursuit of a novel idea. That happens all the time. It’s about what researchers do in the face of disconfirming evidence that matters. How was it that the horse could answer questions (e.g., read what time it was) without even looking at the stimulus (e.g, watch)? How was it that the horse could only answer questions if the assistant knew the answers ahead of time? How was it that the horse would paw ad infinitum if the spectator (who knew the answer) didn’t tell the assistant (who was blinded to the answer) when the horse had reached the correct response? And, how was it that the horse couldn’t count when his owner was out of visual and auditory range, but could when the owner was nearby?

Based on the research of two investigators, Oskar Pfungst and Ernst Timaeus, eight sources of cuing by Von Osten and others working with the horse have been identified (Umiker-Sebeok and Sebeok, 1981):

1)    Eyes: blinking, changes in direction

2)    Head: head movements upwards, downwards and sideways

3)    Mouth: changes in lip configuration

4)    Body: changes in postural tension

5)    Hands: hand movements

6)    Jaw: changes in muscle tension

7)    Voiceless counting along

8)    Breathing: patterns of inhalation

It turns out, when people are in a state of expectation, their bodies reflexively tense up. Think about playing Bingo. You’re one square away from winning the game and the person is about to call out the number. You sit up straight, hold your breath, focus your eyes on the card, and hold a marker in your hand ready to place it on the Bingo card. The person calls out the number. You either win or lose, but in either case, your body relaxes because you now know which letter and number have been called.

The same thing happened when Hans was pawing an answer to a number. If the audience and trainer knew the answer was “6,” their muscles would tense until the horse pawed “6,” then they’d relax, probably clap or cheer, and the horse would get a carrot. All good.

In the case of skeptics, their bodies stayed tensed, most likely because they lacked an expectation that the horse could actually count, and, therefore did not give off any cues (i.e., relaxed their bodies) until well after the horse had passed the desired number.

Certainly, an audience primed by newspaper reports or word-of-mouth anecdotes of the horse’s intelligence would come to these events already believing that the claims about Hans could be true. This belief would increase their chances of remembering the “hits” and forgetting the “misses” and reinforcing their already held belief that the horse could count. They would be focusing on the horse’s accomplishments (again, reinforcing their belief) and unaware of their own behaviors contributing to the “success” of the horse’s responses.

If Von Osten had an awareness of these physical cues, he did not let on and, was in that sense, a great salesperson. He may or may not have had internal doubts about the cuing, but outwardly claimed he was not influencing the horse. He protested against double blind procedures, finding it easier for Hans to give the correct answers when he, too, knew the answers to the questions being asked. His reputation and financial stake in asserting the intelligence of his horses, most likely, contributed to the rigidity of his thinking about the issue.

So, as we can see, Clever Hans isn’t about the horse. In fact, the horse was just doing what horses do: keenly observing his handler and behaving in ways that would increase his chances of getting food. If it meant pawing at a board 14 times, then so be it. Instead, Clever Hans is a cautionary tale of how easy it is for researchers and promoters to overlook their own behaviors in pursuit of a wondrous, miraculous, but ultimately pseudoscientific story.

If some of the issues surrounding Clever Hans are reminiscent of Facilitated Communication (FC), it’s because these same, non-conscious cues are built-in to human communication. They can’t be turned on or off at will and are present during all kinds of interactions, be they human- to-animal or human-to-human. Regardless of how sincere a facilitator is or how strict the written guidelines are against influencing the written output, cuing can and does occur, whether the facilitator is conscious of it or not. And, as we have learned from Clever Hans, or rather, in examining the behavior of the assistant, von Osten, these cues can be so subtle that outside observers can be fooled into thinking the communications are real. We owe it to the individuals being subjected to FC and, I’d argue, to the reputations of individuals practicing the technique, to be absolutely sure that the facilitators, like von Osten before them, are not the ones controlling the written output.

References and Recommended Reading:

Anonymous. (1904, Septebmer 24). A Reasoning Horse. Scientific American. 91 (13), 213. Scientific American, a division of Nature America, Inc.

Heinzen, T., Lilienfeld, S., Nolan, S.A. (2015). The Horse That Won’t Go Away: Clever Hans, Facilitated Communication, and the Need for Clear Thinking. McMillan Learning ISBN 978-1464145742

Muckermann, H. (1904, November 12). The Uncleverness of “Clever Hans.” Scientific American. 91 (20), 335. Scientific American, a division of Nature America, Inc.

Pfungst, O. (1911). Clever Hans (The Horse of Mr. Von Osten): A Contribution to Experimental Animal and Human Psychology. New York: Henry Holt and Company.

Umiker-Sebeok, J. and Sebeok, T.A. (1981). Clever Hans and Smart Simians: The Self-fulfilling Prophecy and Kindred Methodological Pitfalls. Anthropos. Bd. 76, H. 1./2., 89-165. Nomos Verlagsgesellschaft mbH.

Wegner, D.M., Fuller, V.A., and Sparrow, B. (2003, July). Clever hands: uncontrolled intelligence in facilitated communication, Journal of Personality & Social Psychology, 85 (1), 5-19. DOI: 10.1037/0022-3514.85.1.5