Clever Hans performs

Clever Hans (in German, der Kluge Hans) was a horse that was claimed to have been able to perform arithmetic and other intellectual tasks. Frontispiece of first volume of Grimms Kinder- und Hausmärchen (1812). ... German (called Deutsch in German; in German the term germanisch is equivalent to English Germanic), is a member of the western group of Germanic languages and is one of the worlds major languages. ... Binomial name Equus caballus Linnaeus, 1758 The horse (Equus caballus, sometimes seen as a subspecies of the Wild Horse, Equus ferus caballus) is a large odd-toed ungulate mammal, one of ten modern species of the genus Equus. ... Arithmetic tables for children, Lausanne, 1835 Arithmetic or arithmetics (from the Greek word αριθμός = number) is the oldest and most elementary branch of mathematics, used by almost everyone, for tasks ranging from simple day-to-day counting to advanced science and business calculations. ...

After formal investigation in 1907, psychologist Oskar Pfungst demonstrated that the horse was not actually performing these mental tasks, but was watching the reaction of his human observers. Pfungst discovered this artifact in the research methodology, wherein the horse was responding directly to involuntary cues in the body language of the human trainer, who had the faculties to solve each problem. The trainer was entirely unaware that he was providing such cues.^{[citation needed]} Year 1907 (MCMVII) was a common year starting on Tuesday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Monday of the 13-day-slower Julian calendar). ... A psychologist is an expert in psychology, the systematic investigation of the human body, including behavior, cognition, and affect. ... This article or section may contain original research or unverified claims. ... For other uses, see Body language (disambiguation). ...

In honour of Pfungst's study, the anomalous artifact has since been referred to as the Clever Hans effect and has continued to be important knowledge in the observer-expectancy effect and later studies in animal cognition. The observer-expectancy effect, in science, is a cognitive bias that occurs in science when a researcher expects a given result and therefore unconsciously manipulates an experiment or misinterprets data in order to find it. ... Animal cognition, is the title given to a modern approach to the mental capacities of animals other than humans. ...

Spectacle

During the late nineteenth century, the public was especially interested in animal intelligence due in a large part to Charles Darwin’s then recent publications. The term Animal intelligence is currently used in three distinct but overlapping ways: as a synonym for animal cognition, to pose the question “are animals intelligent?”, or to denote a discussion of relative levels of intelligence in different animal species. ... For other people of the same surname, and places and things named after Charles Darwin, see Darwin. ...

Hans was a horse owned by a Mr. von Osten, who was a high school math teacher, an amateur horse trainer and phrenologist, and something of a mystic.^[1] Hans was taught to add, subtract, multiply, divide, work with fractions, tell time, keep track of the calendar, differentiate musical tones, and read, spell, and understand German. Von Osten would ask Hans, "If the eighth day of the month comes on a Tuesday, what is the date of the following Friday?” Hans would answer by tapping his foot. Questions could be asked both orally, and in written form. Von Osten exhibited Hans throughout Germany, and never charged admission. Hans's abilities appeared on page six of the New York Times.^{[citation needed]} Phrenology (from Greek: φρην, mind and λογος, study) is a theory which claims to be able to determine character and personality traits and criminality on the basis of the shape of the head (reading bumps). Developed by German physician Franz Joseph Gall around 1800, and very popular in the 19th...

Investigation

Due to the large amount of public interest, the German board of education appointed a commission to investigate von Osten's scientific claims. Philosopher and psychologist Carl Stumpf formed a panel of 13 people, known as the Hans Commission. This commission consisted of a veterinarian, a circus manager, a Cavalry officer, a number of school teachers, and the director of the Berlin zoological gardens. This commission concluded in September, 1904 that no tricks were involved in Hans’ performance.^[2] The commission passed off the evaluation to Pfungst, who tested the basis for these claimed abilities by: A philosopher is a person who thinks deeply regarding people, society, the world, and/or the universe. ... A psychologist is an expert in psychology, the systematic investigation of the human body, including behavior, cognition, and affect. ... Carl Stumpf (21 April 1848 - 25 December 1936) was a philosopher and psychologist. ...

1. Isolating horse and questioner from spectators, so no cues could come from them
2. Using questioners other than the horse's master
3. By means of blinders, varying whether the horse could see the questioner
4. Varying whether the questioner knew the answer to the question in advance.

Using a substantial number of trials, Pfungst found that the horse could get the correct answer even if von Osten himself did not ask the questions, ruling out the possibility of fraud. However, the horse got the right answer only when the questioner knew what the answer was, and the horse could see the questioner. He observed that when von Osten knew the answers to the questions, Hans got 89 percent of the answers correct, but when von Osten did not know the answers to the questions, Hans only answered six percent of the questions correctly.
Pfungst then proceeded to examine the behaviour of the questioner in detail, and showed that as the horse's taps approached the right answer, the questioner's posture and facial expression changed in ways that were consistent with an increase in tension, which was released when the horse made the final, "correct" tap. This provided a cue that the horse could use to tell it to stop tapping. A set of blinders, also known as blinkers, is a set of leather straps attached to the bridle of a horse to prevent it from seeing to its side. ... While not moving, a human can be in one of the following main positions. ...

The social communication systems of horses probably depend on the detection of small postural changes, and this may be why Hans so easily picked up on the cues given by von Osten (who seems to have been entirely unaware that he was providing such cues). However, the capacity to detect such cues is not confined to horses. Pfungst proceeded to test the hypothesis that such cues would be discernible, by carrying out laboratory tests in which he played the part of the horse, and human participants sent him questions to which he gave numerical answers by tapping. He found that 90% of participants gave sufficient cues for him to get a correct answer. Animal communication is any behaviour on the part of one animal that has an effect on the current or future behaviour of another animal. ...

Even after this official debunking, von Osten, who was never persuaded by Pfungst's findings, continued to show Hans around Germany, attracting large and enthusiastic crowds.^[3]

The 'Clever Hans' effect

Pfungst made an extremely significant observation. After he had become adept at giving Hans performances himself, and fully aware of the subtle cues which made them possible, he discovered that he would produce these cues involuntarily regardless of whether he wished to exhibit or suppress them. This gives the phenomenon an importance which could hardly be exaggerated. Its recognition has had a large effect on experimental design and methodology for all experiments whatsoever involving sentient subjects (including humans). The risk of Clever Hans effects is one strong reason why comparative psychologists normally test animals in isolated apparatus, without interaction with them. However this creates problems of its own, because many of the most interesting phenomena in animal cognition are only likely to be demonstrated in a social context, and in order to train and demonstrate them, it is necessary to build up a social relationship between trainer and animal. This point of view has been strongly argued by Irene Pepperberg in relation to her studies of parrots (Alex), and by Alan and Beatrice Gardner in their study of the chimpanzee Washoe. If the results of such studies are to gain universal acceptance, it is necessary to find some way of testing the animals' achievements which eliminates the risk of Clever Hans effects. However, simply removing the trainer from the scene may not be an appropriate strategy, because where the social relationship between trainer and subject is strong, the removal of the trainer may produce emotional responses preventing the subject from performing. It is therefore necessary to devise procedures where none of those present knows what the animal's likely response may be. Comparative psychology, taken in its most usual, broad, sense, refers in to the study of the behaviour and mental life of animals other than human beings. ... Dr. Irene Pepperberg (born April 1, 1949, Brooklyn, New York) is a scientist noted for her studies in animal cognition, particularly in relation to parrots. ... Systematics (but see below) Family Cacatuidae (cockatoos) Subfamily Microglossinae (Palm Cockatoo) Subfamily Calyptorhynchinae (dark cockatoos) Subfamily Cacatuinae (white cockatoos) Family Psittacidae (true parrots) Subfamily Loriinae (lories and lorikeets) Subfamily Psittacinae (typical parrots and allies) Tribe Arini (American psittacines) Tribe Cyclopsitticini (fig parrots) Tribe Micropsittini (pygmy parrots) Tribe Nestorini (kakas and... Alex (1976 - September 6, 2007[1]) was an African Grey Parrot and the subject of a thirty-year (1977-2007) experiment by animal psychologist Irene Pepperberg, initially at the University of Arizona and later at Harvard and Brandeis University. ... Type species Simia troglodytes Blumenbach, 1775 distribution of Species Pan troglodytes Pan paniscus Chimpanzee, often shortened to chimp, is the common name for the two extant species of apes in the genus Pan. ... Washoe (around September of 1965[1] - October 30, 2007) was a chimpanzee who was the first non-human to learn American Sign Language. ...

For an example of an experimental protocol designed to overcome the Clever Hans effect, see Rico (Border Collie). Rico (born: December 1994) is a Border Collie dog who made the news after being studied by animal psychologist Juliane Kaminski from the Max Planck Institute for Evolutionary Anthropology in Leipzig after his owners reported that he understood more than 200 simple words. ...

As Pfungst's final experiment makes clear, Clever Hans effects are quite as likely to occur in experiments with humans as in experiments with other animals. For this reason, care is often taken in fields such as perception, cognitive psychology, and social psychology to make experiments double-blind, meaning that neither the experimenter nor the subject knows what condition the subject is in, and thus what his or her responses are predicted to be. Another way in which Clever Hans effects are avoided is by replacing the experimenter with a computer, which can deliver standardized instructions and record responses without giving clues. In psychology and the cognitive sciences, perception is the process of acquiring, interpreting, selecting, and organizing sensory information. ... Cognitive Psychology is the school of psychology that examines internal mental processes such as problem solving, memory, and language. ... The scope of social psychological research. ... The double blind is ray charles is ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesof the scientific method, used to prevent research...

Trivia

Trivia sections are discouraged under Wikipedia guidelines. The article could be improved by integrating relevant items and removing inappropriate ones.

• Both von Osten and Hans were notoriously bad tempered and prone to rage when the horse did not perform well. Pfungst suffered more than one horse bite during his investigation.^[4]

• Der Kluge Hans - Clever Hans, was the nickname acquired by a young military officer Günther von Kluge in admiration of his brilliance. Von Kluge went on to become one of the most able Field-Marshals of the Third Reich.

Image File history File links Broom_icon. ... Günther “Hans” von Kluge (October 30, 1882 – August 19, 1944), was a German military leader. ...

In popular culture

In an episode of The Simpsons ("Smart and Smarter"), Lisa Simpson becomes jealous of her baby sister Maggie after Maggie is "discovered" to have an even higher IQ than the precocious Lisa. Later in the episode, Lisa is relieved to find that she had been unconsciously cueing Maggie's "correct" IQ-test answers. Simpsons redirects here. ... For the The Suite Life of Zack & Cody episode, see Smart & Smarterer Smart and Smarter is the thirteenth episode of The Simpsons fifteenth season. ...

Australian pop band The Lucksmiths perform a song called "Clever Hans" on their first album. The song features horse imagery but no direct references to its namesake. The Lucksmiths are an independent pop band from Melbourne, Australia who formed in 1993 and have been associated with the genres of indie pop, anti-folk and retro-pop. ...

An episode of The Wild Thornberrys (The Great Bangaboo, airdate: 3/23/1999) features a traveling showman calling himself "The Great Bangaboo" who claims he can talk to animals. To prove this, he performs a show with a donkey that he claims can solve math problems. He displays a card that says "2+2=?" to the audience, then "asks" the donkey for an answer by letting out a plain and simple "Hee-haw!" The audience sees the donkey stomping his foot four times as if to say the answer to "2+2?" is four. However, an intentional view from backstage reveals that the showman pulls with his cane on a tangled system of ropes attached to a broom that pokes the donkey through a covered-up hole in the backdrop, making the donkey instinctively stomp his foot. The Wild Thornberrys was an American animated television series. ...

Sources

• ^  Hothersall, David. History of Psychology. McGraw-Hill. 2004.
• Pfungst, O. (1911). Clever Hans (The horse of Mr. von Osten): A contribution to experimental animal and human psychology (Trans. C. L. Rahn). New York: Henry Holt. (Originally published in German, 1907).
• BERLIN'S WONDERFUL HORSE; He Can Do Almost Everything but Talk—How He Was Taught. The New York Times (1904-09-04). Retrieved on 2008-02-26.
• "CLEVER HANS" AGAIN.; Expert Commission Decides That the Horse Actually Reasons.. The New York Times (1904-10-02). Retrieved on 2008-01-02.

1904 (MCMIV) was a leap year starting on a Friday (see link for calendar). ... is the 247th day of the year (248th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... is the 57th day of the year in the Gregorian calendar. ... 1904 (MCMIV) was a leap year starting on a Friday (see link for calendar). ... is the 275th day of the year (276th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... is the 2nd day of the year in the Gregorian calendar. ...

See also

• Pygmalion effect
• Lady Wonder a horse with purported telepathic abilities.
• Ideomotor Effect

The Pygmalion effect (or Rosenthal effect) refers to situations in which students perform better than other students simply because they are expected to do so. ... The ideomotor effect is a psychological phenomenon wherein a subject makes motions unconsciously (i. ...

External links

• Classics in Psychology: Oskar Pfungst's Clever Hans (The Horse of Mr. von Osten), by Robert H. Wozniak
• Clever Hans the Math Horse