Natural intelligence
Natural intelligence

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Natural intelligence

2.6 A dreadful warning

Finally, a case study to serve as a warning against the ever-present danger of anthropomorphism.

Case Study 7: ‘Clever Hans’

Hans von Osten lived in Berlin around the turn of the nineteenth century and was famous throughout Germany for his ability to solve mathematical problems such as 3 x 4 or 3 x 9. Not so special, you might think – but ‘Clever Hans’ was a horse. His owner, Herr von Osten, would write an expression such as 2 x 3 or 5 x 2 on a blackboard and Hans would respond by tapping the ground with his hoof the right number of times. He sometimes got the answer wrong, but his success rate was much higher than chance. People came from far and wide to watch Hans’s act and many scientists of the time accepted that he understood arithmetic and could calculate.

Exercise 8

What do you think? Are other explanations possible? Did Hans understand arithmetic? Could he calculate?


Alas, no. The psychologist Oskar Pfungst was able to show that Hans was not even looking at the blackboard, which we may assume meant nothing to him. He was watching his master. He had learned to pick up tiny, unnoticed scraps of body language which told him when was the moment to stop tapping his hoof. If no one was present as the problem was presented, he simply tapped at random.

Earlier in this course we defined anthropomorphism as a tendency to call behaviour ‘intelligent’ only if we can identify it with our own. Anthropomorphism is an ever-present danger when we try to make inferences about animal intelligence. Here we have an inverted case of the same problem. Looking at Hans’s behaviour, it is all too easy to imagine he had mental states – an awareness of number and sequence, an appreciation of the meaning of arithmetic operators – which he simply did not possess. He was a horse. The mental world of horses, if they have one at all, must surely be utterly remote from ours.


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