Skip to main content

Jaensch, Erich

Jaensch, Erich



Erich Rudolf Jaensch, German psychologist, was born in Breslau in 1883 and died in Marburg an der Lahn in 1940. After studying physics and mathematics at Göttingen he became a student of G. E. Müller and Hermann Ebbinghaus, to whom he dedicated his first book (1909). In 1913 he was appointed to a chair of philosophy at Marburg and founded the Psychological Institute there.

It is characteristic of Jaensch that in all his work, beginning with his earliest (1909), he moved beyond the particular problem with which he had started to the applications of his results. In this first book, for example, he moved from psychophysical experiments in visual acuity and the like to the pathology of vision. From the simpler visual phenomena he proceeded to experiments on the perception of space (1911) and extended his general discussion into the fields of aesthetics and epistemology. His work on size and color constancies (1914), which later was integrated with his experiments on eidetic imagery (1925), was speculatively extended into a comprehensive theory of psychophysiological development, personality theory, and race psychology, as well as a theory of the structure and development of the world as perceived and known (1923).

In Über den Aufbau der Wahrnehmungswelt (1923) Jaensch showed, anticipating Wittgenstein, that the world of perceptual experience is not a product or precipitate of external stimuli alone, or of inner (psychological) contents alone; it is a product of both, in which inner and outer responses interpenetrate. Memory has a stratified structure of primordial and later contents, with both phylogenetic and ontogenetic roots, and these two kinds of content emerge as such in various states of the person (e.g., in dark-adapted vision and under the influence of drugs such as alcohol). A simple example of the differential interpenetration of outer and inner is to be found in tachistoscopic experiments on reading. At one extreme, a briefly exposed mutilated word is “seen” by the subject as a meaningful one, even to the extent that on successive exposures it is reported as being much clearer, “in quite black print,” “standing out from the screen”; subjects at the other extreme read letter by letter in an analytic rather than a synthetic way even when the word is long, meaningful, and well known to them. Similarly, in experiments on space orientation, the first type of subject is less “stimulus bound” than is the second (cf. the work of H. A. Witkin).

Outside central Europe, Jaensch is best known through his work on eidetic images (El). A positive El is a particularly strong visual afterimage, which has great clarity and which in its most pronounced form is reproduced in the colors of the stimulus object, often in very fine detail. Its frequency is highest in young children. Its opposite is the negative El, which appears in complementary colors.

While common afterimages (AI) are due to primitive retinal functions and obey Emmert’s law (their size is proportional to the distance at which they are projected), El do not obey this law but tend toward size constancy. Jaensch thus supposed that El arise from the functioning of centers that are phylogenetically earlier and that they play a part in forming the memory of objects. In memory, of course, objects are constant in size. The development of visual size constancy is therefore explained by supposing that the perceived visual object is a fusion of retinal image and memory “image,” which in ontogenesis was first an El Similar but more complex evolutionary considerations are put forward to explain the origin of color constancy and the laws of color contrast and transformation.

Having at first classified El as “sensations” and as not normal, Jaensch thus soon recognized that, instead, they have a conceptual character, that they are an extension or variant of what an adult calls an “idea” or a “memory image of an idea,” that attention is necessary for their formation, and that they do occur normally in development.

The intraorganismic functions that generate visual experiences, memories, and ultimately all concepts are stratified. The strata are the products of ontogenetic developmental stages. In phylogenetic development ontogenesis is recapitulated, but different experiences create the unique individual as a variant of basic biopsychological types. The bio-psychological typology (see below) in turn led Jaensch to a general theory of concept formation, of the different classes of anomalous color vision, of the ontogenesis of color and movement perception, and finally into a somewhat grandiose explanation of racial and cultural phenomena.

The two extreme types of El, according to Jaensch and his school, are characteristic of two physical types: the B-type (from Basedow’s disease, i.e., hyperthyroidism) and the T-type (since it has tetanoid stigmata). Different chemotherapeutic treatments are needed by these types if they are pathologically exaggerated. Jaensch’s brother, a physician and physiologist, based the greater part of his clinical and pharmacological research on the B and T types (Walther Jaensch 1926; 1930).

Jaensch attempted to build a comprehensive theory of personality as well as a typology. His experimental and theoretical writings and those of his school are very extensive; the best coverage in a single volume is in Grundformen menschlichen Seins (1929). His typology tries to avoid the arbitrary categorization of clusters of individual differences and is based on general principles and a limited number of dimensions. In modern terms Jaensch could be classified as a cognitive theorist and an ego psychologist.

The main principles Jaensch called Kohärenz and Integration. By Kohärenz he meant the degree to which a person is anchored in and responds to the demands of reality. By Integration he meant the degree to which stimuli for one sensory modality or complex stimuli for one molar behavioral modality interact to modify or “integrate” the total response. For example, if a person with a high degree of integration has a depressing experience he will tend to see even a bright sunny day as literally gloomy, suffer other distortions of his pattern and space perceptions, and also show marked physiological effects.

This way of defining Integration implies that there are individual differences in the extent of invariance of the structures of perceptual and molar behavioral events. For some persons it is true to say that they exhibit invariant “traits”; for others, “traits” have degrees of invariance depending on context, stimulus, and intraorganismic state. The use here of the word “traits” highlights the degree of similarity between Jaensch’s view of the dynamics of behavior and Raymond B. Cattell’s view of “source traits.” The difference between these theorists is that Jaensch based his theoretical and experimental work on a theory of the relation between the biological and psychological properties of the organism and its stimulus environment, not on a heuristic collection of data treated by the mathematical device of factor analysis.

Jaensch’s integrate type is one who might be said to act as a dynamic whole, whose ego has low rigidity. He responds easily to stimuli (physical, verbal, and social), is imaginative and creative, prefers romantic art forms to classic, impressionism to expressionism, expressive movements to the standardized responses of organized games, literature to mathematics, speculative philosophy (e.g., Leibnitz and Plato) to analytic philosophy (e.g., Descartes and Aristotle). At lower levels, he produces more W-responses than D or Dd on the Rorschach, has high values for the Müller–Lyer illusion, and is percept-dominated in that his perception of objects is not strongly affected by changes of illumination, has low perseveration scores, adapts quickly, and in general is strongly sympathetico-tonic. His physical type tends to be slender, clear-skinned, with large “luminous” eyes (the extreme being the B-type, which has the stigmata of exophthalmic goiter). His imagery is predominantly visual and, like all his actions, strongly influenced by emotional states.

The polar opposite of this I-type is the des-integrate type. He prefers expressionistic or other bizarre forms of art, has jerky movements, is analytic instead of synthetic, is cold, detached, and so on. Between these extremes there are several classes of I-types, the two important ones being the “inwardly integrate” or li-type and the S-type (so labeled because one of his characteristics is a proneness to synesthesias). The li-type has less Kohärenz with objective reality than the I-type but has strongly integrated sentiment and value systems; he is the typical German idealistic thinker. The S-type tends to negative cynicism and to destructive skepticism, especially about social and value systems.

Jaensch speculated broadly about the place of these types in various civilizations and their frequencies in various climates. Thus, he thought that the primitive peoples of the Pacific must be integrates and that predominant in southern Europe were the I1 and I2 types, in northern Europe the li or inwardly integrate type, in France the S-type.

These unbridled generalizations on a totally insufficient statistical basis led him to support some of the theories of race current in Germany in the 1930–1940 era. Naturally, he regarded the Nordic li as the “best” type, while the dominance of the S-type among the Jews destined them for biological reasons to be the destroyers of idealism and Volksgemeinschaft. However, he did believe that education could and should play a formative role in assisting the development of children from their early state of labile responsiveness to a higher state of inward integration, and his educational theories would be well accepted in “progressive” schools, which pay attention to the whole child and try to get away from the excessive concentration on the particulate fragments of intellectualized syllabuses, analytic thinking, and passive ingestion.

His “functional” and phylogenetic approach to the study of personality is important for students of existentialist philosophy, as it tried to give existentialism an empirical foundation in the theory of personality and perception. Jaensch always cited the whole range of his work in visual perception and the synesthesias to show in what sense personality is an integration, not a conglomerate, of traits. His biopsychological theories are related to those of Hans Driesch, and much of his logical development of the concept of integration is pertinent to the work of some modern system theorists like Ludwig von Bertalanffy. Similarly, Gordon W. Allport’s “functional autonomy” and Ernst Spranger’s “styles of living” have affinities with many of Jaensch’s concepts.

That Jaensch’s work was not taken up by English-speaking psychologists is hardly surprising. It appeared when behaviorism was rapidly gathering strength, when S–R was the most widely accepted concept, when the idea of states of consciousness was rejected, and tendencies to indulge in philosophical “speculations” were firmly suppressed. But now that the nonstatistical work of Piaget is widely accepted and ego psychology is almost respectable, Jaensch’s work may once again be studied after half a century of neglect. In one sense he was like present-day factorists, in that he made a large number of different experimental tests instead of merely reporting individual differences in this or that aspect. He was unlike factorists, however, in his continuing effort to reduce the multiplicity of human responses and conscious experiences to, say, three or four functions rather than an indefinitely increasing number of “factors”; above all, Jaensch differed from the factorists in trying to find “functions” that are firmly rooted in the biology of the organism without thereby becoming a reductionist.

O. A. Oeser

[Relevant articles are those onDevelopmental psychology, article ona theory of development; Perception, articles onperceptual constancyandillusions and aftereffects; Personality: contemporary viewpoints; Projective methods, article onthe rorschach test; Systems analysis, article onpsychological systems; Traits; Vision, article oncolor vision and color blindness.


1909 Zur Analyse der Gesichtswahrnehmungen: Experimentell-psychologische Untersuchungen nebst Anwendungen auf die Pathologic des Sehens. Zeitschrift für Psychologic Supplement no. 4.

1911 Über die Wahrnehmung des Raumes: Eine experimentell-psychologische Untersuchung nebst Anwen-dung auf Ästhetik und Erkenntnislehre. Zeitschrift für Psychologic Supplement no. 6.

(1914) 1930 Über Grundfragen der Farbenpsychologie: Zugleich ein Beitrag zur Theorie der Erfahrung. Leipzig: Barth.

(1923) 1927–1931 Über den Aufbau der Wahrnehmungswelt und die Grundlagen der menschlichen Erkenntnis. 2 vols. 2d ed. Leipzig: Barth.

(1925) 1930 Eidetic Imagery and Typological Methods of Investigation: Their Importance for the Psychology of Childhood, the Theory of Education, General Psychology, and the Psychophysiology of Human Personality. New York: Harcourt. → First published in German.

1929 Grundformen menschlichen Seins. Berlin: Elsner.

1930 a Studien zur Psychologic menschlicher Typen. Leipzig: Barth.

1930 b Über den Aufbau des Bewusstseins. Part 1: Die Kohärenz mit der Aussenwelt in der Kindheit und die Kohärenzpetref akte in der bleibenden Wahrnehmungsstruktur. Zeitschrift für Psychologie Supplement no. 16.

1933 Neue Wege der Lichtbiologie unter funktionellem und ganzheitlichem Betrachtungsgesichtspunkt. Leipzig: Barth.


AnschÜtz, Georg 1953 Psychologie. Hamburg (Germany): Meiner.

Jaensch, Walther 1926 Grundziige einer Physiologie und Klinik der psychophysischen Personlichkeit. Berlin: Springer.

Jaensch, Walther 1930 Die Hautkapillarmikroskopie am Lebenden. Pages 865–940 in Emil Aberhalden (editor), Handbuch der biologischen Arbeitsmethoden. Section 9, part 3, no. 5. Berlin: Urban & Schwarzenberg.

Krudewig, Maria 1953 Die Lehren von der visuelien Wahrnehmung und Vorstellung bei Erich Rudolf Jaensch und seinen Schülern. Meisenheim am Glan (Germany): Hain.

Wellek, Albert 1955 Ganzheitspsychologie und Strukturtheorie. Bern: Francke.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Jaensch, Erich." International Encyclopedia of the Social Sciences. . 18 Jun. 2019 <>.

"Jaensch, Erich." International Encyclopedia of the Social Sciences. . (June 18, 2019).

"Jaensch, Erich." International Encyclopedia of the Social Sciences. . Retrieved June 18, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.