German-American psychologist, one of the founders of Gestalt psychology with Kurt Koffka. Wolfgang Köhler gained fame with his studies on cognitive processing involved in problem-solving by animals. Köhler argued that animals do not learn everything through a gradual trial-and-error process, or stimulus-response association. His tests in Tenerife in the 1910s with chimpanzees suggested that these animals solved problems by understanding – like human beings, they are capable of insight learning, the "aha!" solutions to problems. Köhler also discovered with von Restoff the isolation effect in memory, contributed to the theory of memory and recall, and developed a non-associationist theory of the nature of associations.

"Sultan tries to reach the fruit with the smaller of the two sticks. Not succeeding, he tears at a piece of wire that projects from the netting of his cage, but that too is in vain... He suddenly picks up the little stick once more, goes up to the bars directly opposite the long stick, scratches it towards him with the "auxiliary," seizes it, and goes with it to the point opposite the objective (the fruit), which he secures." (from The Mentality of Apes, 1925)

Wolfgang Köhler was born in Reval (now Tallinn), Estonia, the son of German parents. When he was six, the family moved to Germany, and settled in Wolfenbüttell. Köhler attended the universities of Tübingen (1905-1906), Bonn (1906-1907) and Berlin. At the University of Berlin he studied psychics under Max Planck and psychology under Karl Stumpf. Köhler received his Ph.D. in 1909 for a dissertation on psycho-acoustics. In the same year he started to work at the Psychological Institute in Frankfurt-am-Main. There he met Max Wertheimer and Kurt Koffka, with whom he laid the foundations of the Gestalt psychology. It was born as a reaction to the behavioristic theories of Watson and Pavlov and focused mainly on the nature of perception. For German word Gestalt Köhler gave it new dimensions: "In the German language – at least since the time of Goethe, and especially in his own papers on natural science – the noun 'gestalt' has two meanings: besides the connotation of 'shape' or 'form' as a property of things, it has the meaning of a concrete individual and characteristic entity, existing as something detached and having a shape or form as one of its attributes. Following this tradition, in gestalttheorie the word 'gestalt' means any segregated whole."

As against the behaviourist's mechanical model of stimulus-response, Köhler used what he called a dynamic model of human behavior, which emphasized the active role of organization in perception. His stand had much in common with Goethe's view of nature – Goethe began his scientific studies in response to a desire to see an alternative to the mechanistic Newtonian science of his day. In his studies of plants Goethe saw that with the model of Urplanze (the "original plant") it would be possible to go on for ever inventing plants and to know that their existence is logical – and if they do not actually exist, they could. Later the Austrian philosopher Ludwig Wittgenstein took this idea and developed it further. According to Wittgenstein, we see or recognize a Gestalt, not in the sense that we see a physical object, but in the same sense that we see or recognize a likeness. Köhler's treatment of the concept Wittgenstein criticized in Lectures on Philosophical Psychology and Remarks on the Philosophy of Psychology. (see Ray Monk's biography Ludwig Wittgenstein, 1991).

Köhler's collaboration with Koffka and Wertheimer was interrupted when he became director of the Anthropoid Station on Tenerife, one of the Canary Islands. Due to World War I, which broke out shortly after his arrival, his stay was prolonged for seven years. While at the station, Köhler conducted experiments on chimpanzees, recording their ability to devise and use simple tools and solve problems. He also made tests on chickens and demonstrated that they could develop a relationship. Köhler's The Mentality of apes was published in German in 1917 and translated into English in 1925. Noteworthy, Tenerife was an unlikely place for such research: chimpanzees are not native to the region. Besides doing scientific work, Köhler informed German military officials with a radio whether or not British vessels were in the vicinity. Köhler's home was several times searched by Spanish authorities.

Köhler's most intelligent chimpanzee was Sultan. In the simplest case the desired object was placed on the other side of a fence at the end of an alley. The ape, according to Köhler, conceptualized the Gestalt by turning back down the alley and going around to the other side of the fence. In one famous test there were two bamboo sticks in a chimpanzee's cage, but neither of them was long enough to reach a banana outside the cage. After many attempts the chimpanzee pushed the thinner of the two sticks into the hollow inside the thicker one and then drew the banana toward himself. The animals also learned to use boxes as "clime-upon-ables" to reach desirable lures. However, Köhler's tests were not very well controlled. Often several chimpanzees were in the cage at the same time. His critics found a number of alternative explanations, and stated that animals might have learned from imitating one another.

After his return to Germany in the 1920s, Köhler became director of the Psychological Institute at the University of Berlin. He divorced his first wife and married in 1927 a young Swedish student, Lili Harleman. With his colleagues, Wertheimer, Koffka and others, he formed a discussion forum about Gestalt psychology, Psychologische Forschung. In 1925-26 Köhler was a visiting professor at Clark University in the United States. In 1934-35 he was William James Lecturer at Harvard and in 1935 a visiting professor at the University of Chicago.

After the Nazis rose to power, Köhler published an article in Die Deutsche Allgemeine Zeitung, in which he criticized their policy. Referring to his friends, who did not join the Party, he said, "they believe that only the quality of a human being should determine his worth, that intellectual achievement, character, and obvious contributions to German culture retain their significance whatever a person is Jewish or not." In April 1934 the Nazis storm troopers interfered with his work by searching the the Psychological Institute. Köhler protested the action. The goverment decided to dismiss all the assistants in the Institute, who were trained Köhler, and he eventually emigrated to the United States in 1935. There he joined the staff of Swarthmore College as a professor of psychology. His former research assistant Karl Duncker, who had left Germany earlier, suffered from severe bouts of depression and the Köhlers took him in their home to care for him. Duncker committed suicide in 1940. Köhler worked in Swathmore until 1955. After spending a year as a member of the Institute for Advanced Study, Princeton University, he became a research professor at Dartmouth College, Hannover, N.H. In 1956 he was appointed president of the American Psychological Association. Köhler died on June 11, 1967, in Enfield, N.H. His last book, The Task of Gestalt Psychology (1969), was published posthumously.

With the notion of Gestalt Köhler believed he could bring together natural science and the humanites. Dynamics in Psychology (1940) dealt with the relationship between physics and Gestalt psychology. According to Gestaltists, the brain is a physical system whose activity could be understood in terms of field theory. Köhler's ideas influenced Rudolf Arnheim, who further elaborated them in Art and Visual Perception (1954/1974) and Entropy and Art (1971). The gestalt theory of brain functioning was questioned in the 1950s by Karl Lashley, Roger Sperry and Karl Pribram. Köhler had reasoned that the cortex operates as an electric field, and it was found that laboratory animals could still perceive after conductive metal foils had been inserted into their brains.

In The Place of Value in a World of Facts (1938), his William James lectures delivered at Harvard in 1934, Köhler attempted to work out a theory of value, including aesthetic value, on the basis of the phenomenally objective gestalt-quality which he called "requiredness," the demand which one part of the field may have for another. For example, a circle with a small segment missing tends to be seen as a complete circle. Evaluation, Köhler argued, as the direct perception of what ought to be, is but a special case of this requiredness of the phenomenal. Although Köhler made no attempt to develop a detailed theory of particular kinds of value, his followers have formulated general "laws" of perception-phenomena, and elaborated neuro-physiological hypotheses to account for them. Köhler himself distinguished between phenomena (or perception), states of the brain, and other physical things. They all are related. A white square in a black field in the physical world will appear in experience as a white square in a black field which in turn will be represented by a corresponding 'white square in black field' state of the brain. They are not the same kind of things but the formal relationship between states of the world is preserved in the corresponding relationship between states of the brain.

Gestalt psychology. Gestalt: German origin, meaning configuration, pattern, organized whole. The key term of Gestalt psychology was contributed by the Austrian philosopher, Christian von Ehrenfels, in his paper "On Gestalt Qualities" (1890), although the movement itself is usually dated from the pioneering paper of Max Wertheimer, "Experimental Studies on the Perception of Apparent Movement" (1912). The movement arose in part as a reaction against such psychologists as Wundt and Titchner. Titchner argued that individuals perceive on the basis of the stimulus impinging on the sense organ but that they interpret them in accord with what they have learned. To avoid confusing interpretations with true sensations, Tichner wanted to train experts to observe their sensory experiences. This was not accepted by Gestaltites. They emphasized the necessity for dealing with behavior in all its complexity, rather than attempting to analyze it by components.

Gestalt psychology is one of the six main schools of psychology with structuralism, functionalism, associationism, behaviorism and psychoanalysis (Freud, Jung, Adler). The key argument is that the nature of the parts is determined by the whole – parts are secondary to the whole. In perception we, and the animals, are aware directly of a configuration on a structure which is grasped in its totality. That is why, as an example, we hear in music a melody instead of separate notes, and a picture, when enlarged or reduced in size, is seen to be the same image. Objects of art cannot be understood in terms of their parts. Köhler underlined that one must examine the whole to discover what its natural parts are, and not proceed from supposed elements into large entities.

Gestalt psychologists began first in the 1910s to study the phi-phenomenon, a type of illusory perceptual impression of movement produced when, e.g. two stationary, spatially separated lights are flashed in brief succession. Gestalt psychology influenced also philosophy, aesthetics, and art. Ludwig Wittgenstein referred several times to Köhler in his Philosophical Investigations. Arthur Koestler quotes Köhler's The Mentality of Apes in his study The Act of Creation, and describes how a chimpanzee discovers the use of tools and gets the banana with the help of a stick. Koestler states according to a old saying "fortune favours the prepared mind," that "discovery often means simply the uncovering of something which has always been there but was hidden from the eye by the blinkers of habit." Gestalt psychology has been widely criticized on the grounds that the whole could never be different from the sum of its parts.

For further reading: Die Wertheimer-Koffka-Köhlersche Gestalt-theory by B. Petermann (1929); Principles of Gestalt Psychology by K. Koffka (1935); A Source Book of Gestalt Psychology by W.D. Ellis (1938); Gestalt Psychology by D. Katz (1950); Productive Thinking by M. Wertheimer (1959); Whisper of Espionage: Wolfgang Kohler and the Apes on Tenerife by R.A. Ley (1991); Biographical Dictionary of Twentieth-Century Philosophers, ed. Stuart Brown et al. (1996); Cognitive Psychology: A Student's Handbook by Michael W. Eysenck, Mark T. Keane (1997). Books, films: Köhler's famous experiments in perception and learning in apes and chimpanzees gave ground to those science fiction writers who speculated with the evolution. In Pierre Boulle's Planet of the Apes human beings have been replaced by apes, and in Arthur C. Clarke's 2001: A Space Odyssey the civilization starts when apes learn to use weapons. In the famous film King Kong (1933) a giant ape falls in love with a screaming blonde, and is destroyed by technology in New York.

Selected works and translations into English:

• Akustische Untersuchungen. I., 1909 (doctoral dissertation)
• Intelligenzenprüfungen an Anthropoiden, 1917
• Intelligenzenprüfungen an Menschenaffen, 1921 (rev. ed. of Intelligenzenprüfungen an Anthropoiden) - The Mentality of Apes (tr. Ella Winter, 1925)
• Die physischen Gestalten in Ruhe und im Stationaren Zustand, 1920 - Wolfgang Köhler and Gestalt Theory: An English Translation of Köhler's Introduction to die physischen Gestalten for Philosophers and Biologists (tr. R. Arnheim, 1998)
• Gestalt Psychology, 1929 (rev. ed. in 1947)
• The Place of Value in a World of Fact, 1938
• Dynamics in Psychology, 1940 (rev. 1965)
• 'On the nature of associations', 1942 (in Proceedings of the American Philosophical Society 84)
• 'Figural after-effects: an investigation of visual processes', 1944 (in Proceedings of the American Philosophical Society 88)
• Gestalt Psychology: An Introduction to New Concepts in Modern Psychology, 1947
• The Task of Gestalt Psychology, 1969
• The Selected Papers of Wolfgang Kohler, 1971 (edited by Mary Henle)
• Briefe von Wolfgang Ko¨hler an Hans Geitel 1907-1920, 1988 (ed. Siegfried Jaeger)