author
Oskar Pfungst
1874–1933
Best known for unraveling the mystery of Clever Hans, this German psychologist showed how easily people can mistake subtle cues for true intelligence. His work helped shape modern thinking about animal behavior, suggestion, and experimental method.
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About the author
Born in Frankfurt am Main in 1874, Oskar Pfungst was a German comparative biologist and psychologist. He studied philosophy, biology, and medicine in Munich and Berlin, and became known while working with psychologist Carl Stumpf in Berlin.
Pfungst's lasting fame comes from his investigation of Clever Hans, the horse that seemed able to solve arithmetic problems. In 1907 he showed that the animal was not really calculating, but responding to tiny, unintentional signals from people nearby — a finding that later gave rise to what is now called the Clever Hans effect.
He also wrote Clever Hans (The Horse of Mr. von Osten): A Contribution to Experimental Animal and Human Psychology, a book that remains important for readers interested in psychology, animal cognition, and the challenges of careful observation. Sources differ on whether his death year should be listed as 1932 or 1933, so it is safest to note that he died in the early 1930s.