Back about 120 or so years ago, on a day like today, if you had been in the city of Berlin, Germany you might have encountered a strange sight: a man giving a demonstration of a horse that he said could solve math problems.


The man was Wilhelm Von Osten.

In the demonstrations, he would pose a question to his horse, known as Clever Hans.

The horse would respond by nodding its head as if to say “yes,” or by tapping its hoof to signify specific numbers.

The questions could get complicated: Von Osten might ask Hans to add fractions together, or spell out names, or identify colors.

He claimed the horse was reasoning out the answers to the questions, that it was roughly as intelligent as a human teenager.

Critics thought the whole thing was a hoax, but several investigations found no evidence that Von Osten was secretly feeding the horse answers- at least not on purpose.

A psychologist named Oskar Pfungst found a different explanation after conducting several experiments.

He found that Von Osten and other questioners were unconsciously giving Clever Hans cues that guided his answers.

If they knew the answer to a question was, say, nine, their bodies might tense up a bit as the horse counted.

When Hans got to the right answer, the questioner’s body relaxed, and the horse took that as a cue to stop tapping.

Without those cues, Hans couldn’t answer questions correctly.

Today psychologists describe unintentional cues from a questioner as the “Clever Hans effect.”

Though Hans definitely was clever, just in a different way than people thought.

Today in 1989, the town of Avesta, Sweden created the world’s largest Dala horse.

That’s a Swedish symbol, usually a little red wooden horse with an ornate harness.

This one was not little: 43 feet tall, and concrete instead of wood, so it weighed 68 tons.

Clever Hans: The Horse Who Could Do Math (Amusing Planet)

World’s Largest Dalecarlian Horse (Bookofjoe)

Nobody’s as clever as our Patreon backers

Photo via Wikicommons