Clever Hans facts for kids
Clever Hans (in German, der Kluge Hans) was a famous horse from the early 1900s. People thought he could do amazing things like solve difficult math problems and answer complicated questions. But later, scientists found out that Hans was actually getting the right answers by carefully watching the people around him. He was very good at picking up on tiny clues!
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How Hans Seemed So Smart
Hans lived in Germany at the beginning of the 20th century. His owner was a man named Herr Wilhelm von Osten. Mr. von Osten was a teacher who taught math at a school. He was also a hobbyist when it came to training horses.
At this time, many people were very interested in how smart animals could be. This was partly because of the ideas that Charles Darwin had written about.
Mr. von Osten taught Hans to do many things. He taught him to add, subtract, multiply, and divide. Hans could also work with fractions, tell the time and date, and even understand German. When Mr. von Osten asked a question like, "What is 12 plus 12?", Hans would tap his hoof 24 times. Mr. von Osten traveled all over the country with Hans, showing off his incredibly smart horse to everyone.
The Study That Uncovered the Secret
Scientists became very curious about Clever Hans. A psychologist named Carl Stumpf put together a group of people to study what was happening. His assistant, Oskar Pfungst, was the main person investigating Hans.
They noticed that Hans almost always gave the right answer when he could see his owner. He also gave correct answers if someone else asked him a question. This showed that Mr. von Osten was not secretly giving Hans signals on purpose.
Pfungst then tried an experiment. He put special blinders on Hans. These blinders meant the horse could only see straight ahead. If Hans could see the person asking the question, he got the answers right 89% of the time. But if the person asking the question stood to the side, where Hans could not see, his answers were right only 6% of the time. Also, Hans could not answer correctly if the person asking the question did not know the answer themselves.
Pfungst observed Hans very closely. When Hans was close to the right answer, he would start tapping his hoof more slowly. Then he would stop exactly when he reached the correct number. This showed that Hans was watching the person asking the question. He could sense when the person expected him to stop. Mr. von Osten probably didn't even realize he was giving Hans signals just by looking at him. Hans was indeed clever to guess what was wanted from him. But he didn't actually understand the math. The final proof came when Pfungst learned how to signal to Hans himself. By slightly raising his eyebrows, Pfungst could get Hans to give any answer he wanted.
What Was the Clever Hans Effect?
This discovery is now often called the "Clever Hans effect." It's a term used in psychology to describe a situation. It happens when an animal or even a person figures out what someone wants them to do. This happens even if the signals are not given on purpose.
It's very important to remember the Clever Hans effect when testing how intelligent animals or even humans are. For example, if you are testing an animal's true intelligence, it might need to be separated from its trainer. This helps make sure the animal isn't just reacting to clues from the trainer.
However, sometimes an animal might get upset if it can't see its trainer. This could make it harder for the animal to give the right answer. A good way to solve this problem is to create a situation where the trainer doesn't know the right answer either. This way, they can't accidentally give any clues.
The Clever Hans effect is quite famous. It has even appeared in popular culture. For example, there's an episode of The Simpsons called "Smart and Smarter." In this episode, Lisa Simpson gets jealous of her baby sister Maggie. Maggie seems even smarter than Lisa. But then they discover that Maggie has been watching Lisa so carefully that she could sense what the answers were. Lisa is very relieved when she finds this out!
See also
In Spanish: Clever Hans para niños
