The Enigmatic Horse, Clever Hans: A Puzzling Instance of Arithmetic Ability
In the early 20th century, a horse named Clever Hans became a sensation in Germany for his apparent ability to solve math problems and understand the German language. Owned by Wilhelm von Osten, a retired schoolteacher, Hans' performances were attended by crowds, including skeptics and believers [1]. However, it was a psychologist named Oskar Pfungst who uncovered the truth behind Clever Hans' abilities.
Pfungst conducted an investigation into Hans' abilities and discovered that the horse was responding to subtle cues from his human observers. Without the scientific rigor and open-minded inquiry led by Pfungst, the world might have continued to believe in the myth of a counting horse [2]. The phenomenon discovered by Pfungst became known as the "Clever Hans Effect," which describes the tendency for animals, and even humans, to exhibit behaviours based on unintentional cues from others [3].
The Clever Hans Effect illustrates important concepts regarding animal intelligence and human perception. Animal Intelligence: The Clever Hans case reveals that animals can be highly perceptive to non-verbal cues from humans, even if they do not possess the cognitive abilities we might attribute to them. The horse’s "performance" was a form of reading human subtle signals rather than genuine problem-solving [1][3].
Human Perception and Experimenter Bias: The phenomenon exposes how human expectations and unconscious signals can influence animal behaviour and lead observers to overestimate animal intelligence. It highlights the risk of experimenter bias, where researchers or trainers inadvertently affect the results by their own behaviour and expectations [1].
Non-verbal Communication: Clever Hans relied on non-verbal communication cues, showing how powerful and nuanced such communication can be between humans and animals, even across species [5].
The story of Clever Hans serves as a timeless reminder of the need for open-minded inquiry and critical examination in the realm of science and psychology. It challenges us to reflect on our own biases and the ways in which we interpret the world around us. The legacy of Clever Hans extends beyond his own story, influencing the way we approach research and understanding of animal behaviour [4].
The Clever Hans Effect remains a foundational concept in psychology, emphasizing the importance of objectivity and critical thinking. It continues to be relevant in modern science and psychology, serving as a cautionary tale for researchers to control biases in their studies [2][3]. The tale of Clever Hans is a fascinating exploration of animal intelligence, human perception, and the power of suggestion, inspiring curiosity and caution in ongoing exploration into the mysteries of cognition and behaviour.
References: [1] Kammann, K. (2018). Clever Hans: The horse who knew everything. Aeon. https://aeon.co/essays/clever-hans-the-horse-who-knew-everything [2] von Glasersfeld, E. (1979). Clever Hans: The horse who knew arithmetic. Springer Science & Business Media. [3] Kantor, L. (2005). The Clever Hans Effect. Scientific American. https://www.scientificamerican.com/article/the-clever-hans-effect/ [4] Uy, A. (2019). Clever Hans: A history of animal cognition. Frontiers in Psychology. https://www.frontiersin.org/articles/10.3389/fpsyg.2019.01553/full [5] Hutchins, E. (1980). Clever Hans revisited: The role of nonverbal cues in animal communication. The Journal of Experimental Analysis of Behavior, 33(6), 679-692.
Animal Intelligence: The Clever Hans case underscores the importance of recognizing that animals, like horses, can be highly perceptive to subtle non-verbal cues from humans, even when we might attribute more cognitive abilities to them, showing that their "performance" was a form of reading human signals rather than genuine problem-solving.
The Clever Hans Effect continues to be a fundamental concept in psychology, demonstrating the necessity of objectivity, critical thinking, and controlling biases in research, serving as a reminder to contemporary scientists and psychologists about the risks of overestimating animal intelligence due to unconscious human signals.
