Instinct theory

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As instinct theory , more precisely: as " physiological theory of instinctive movements ", the representatives of classical comparative behavioral research (ethology) described an overall concept with the help of which they considered all observable and innate behavior of animals from a uniform point of view. The instinct theory was developed in the 1930s mainly by Konrad Lorenz and Nikolaas Tinbergen and is based on the assumption that the behavior of animals is caused and controlled by clearly distinguishable instincts . "The specific model ideas that were heavily criticized at an early stage - especially with regard to the internal 'driving forces' - are only of historical significance today."

Models to explain behavior

An overall concept such as the physiological theory of instinctual movements makes it possible, on the one hand, to relate certain observations obtained in experiments to other observations, and thereby to discover connections between completely different phenomena. On the other hand - conversely - predictions and regularities can be derived from the basic assumptions of a theory , which give impetus for new questions and experiments. In this sense, the instinct theory ultimately also paved the way for sociobiology and behavioral ecology .

The great advantage of a comprehensively formulated theory is that it can be used to construct descriptive models. Thanks to such models, the statements and results of classic comparative behavioral research have found attention far beyond the academic subject of biology and are still used in school curricula today.

A special feature of the theory advocated by Konrad Lorenz was that he assumed a strict dichotomy of innate and learned behavior, whereby he viewed innate behavior as rigid, unchangeable and, from a phylogenetic point of view, not as a preliminary stage of learned behavior, i.e. behavior modified by experience. Today, however, it is considered certain that innate behavior can also be changed through experience - through learning .

The psychohydraulic instinct model

The “psychohydraulic instinct model” according to Konrad Lorenz

With the help of what he called the "psychohydraulic instinct model", Konrad Lorenz illustrated his principle of double quantification , according to which the intensity of an instinctual act depends on both internal and external factors that trigger behavior: According to him, an instinctive movement is the result of a spontaneously increasing ( inner) readiness to act ( water level in the vessel ), which is fed by action-specific energy ( inflow ) produced in the nervous system . The instinctive movement (triggered effluent water ) usually by a (external) key stimulus ( weight ), but the only one threshold ( spring that urges the valve against the discharge opening overcome) must. Finally, an innate triggering mechanism mediates between stimulus and reaction .

It is true that the strength of the inner willingness to act cannot be measured directly; The strength of the reaction and the strength of the stimulus can, however , be determined quantitatively and thus allow conclusions to be drawn about the amount (the "level") of the specific drive energy.

According to the model, there is a connection between the strength of the reaction on the one hand and the strength of the stimuli and internal factors on the other hand:

  • The stronger the stimulus, the stronger the reaction.
  • The stronger the inner drive (the motivation ), the stronger the reaction.
  • A very strong stimulus can trigger a reaction even if there is a lack of motivation.
  • A very high level of motivation can trigger a reaction even if there is no stimulus.
Example: The intake of food is dependent on two influencing factors: on the one hand on the external conditions, ie on the attractiveness of the food available; on the other hand from the internal conditions, ie the feeling of hunger. When hungry, relatively unattractive food is consumed; if the hunger is very low, extremely attractive food is consumed at best.

An intention movement (suggestion movement) is a weak reaction that can be triggered by weak stimuli or a low drive energy. "It is an expression of the current mood of an animal and can thus serve the mutual understanding of conspecifics by showing the willingness to take a certain action."

Example : If a person approaches a group of seagulls sitting next to each other on the railing on a bridge , those sitting closest to the person fly away, seagulls sitting further away rock a little back and forth (= intentional movements), and even further away seated seagulls show no recognizable reaction (yet).

If an instinctive movement - according to the instinct theory - is not carried out for a long time, "after a long period of non-use, not only does the threshold of the stimuli that trigger a certain type of movement fall, but rather the unused behavior causes the organism as a whole to restless and causes it to actively seek To look for stimulus combinations that trigger them. ”After the term“ appetitive behavior ” coined by Wallace Craig (derived from the Latin “ appetens ”,“ to be eager for something ”), Lorenz called this behavior“ appetite behavior ” . If this search is unsuccessful, according to Lorenz, so much action-specific energy accumulates that the instinctive movement as a result of a lowering of the threshold value is carried out even without a triggering key stimulus. Konrad Lorenz was the first researcher to describe such instinctive movements without a trigger and call them idle actions.

Finally, the concept of instinct theory also includes instinctive movements that occur spontaneously in conflict situations - for example, when two different stimuli act on the individual at the same time - and are not properly interpreted by the observer as the stimuli; the individual reacts neither with the instinctive movement of the species usually triggered by one nor the other stimulus, but with a third movement called the jumping movement .

In 1978 Konrad Lorenz modified his model: The only inflow up to then was replaced by several inflows (external stimuli), whereby each inflow alone does not lead to any behavior, but their sum does. The weight, which symbolized the key stimulus, was replaced by a cup with water, which increases the tank filling or the water pressure and thus opens the valve. In this modified version, exogenous factors that affect motivation were taken into account.

The cybernetic model

Simplified, idealized functional diagram for controlling the behavior when eating, for example, of a dog.
After Hassenstein (1973)

Based on Konrad Lorenz's psychohydraulic instinct model , Bernhard Hassenstein has developed a cybernetic model for building complex behavioral processes. In his book Behavioral Biology of the Child in 1973 he illustrated the control of animal behavior using the example of nutrition and reproduction with the help of several circuit diagrams . In it, Hassenstein summarized on the one hand the undirected search for the desired object, which occurs solely from an inner drive, and the targeted approach to this object as appetite behavior. On the other hand, he delimited the behavior of appetite from the behavior that completes the approach - the so-called final act. According to the model, appetite behavior and end action are controlled by the same drive, but only the end action acts back on the drive. In contrast to the (at least initial) appetite behavior, the final act is also triggered - via an innate trigger mechanism - by environmental stimuli.

Example: behavioral control of food intake:
The external stimulus, i.e. H. the food, (1) is offset in the coincidence element (2) with the strength of the motivation . If both are high enough, food intake behavior is triggered (3). The execution of the behavior is reported back to the instinct center via a sensor (4) and motivation is reduced. At the same time, nutrients are supplied to the body through food intake (5), which increases the controlled variable , i.e. H. the supply status. A measuring sensor (6) registers the supply status and forwards the value to the instinct center, which "evaluates" the value and determines the motivation to eat. This means that with a sufficient supply state and - to a certain extent - also with prolonged "carrying out the behavior of food intake", see feeler (4), which (and which) reduces motivation (/ - n), the outer one The stimulus (attractiveness) of the food must be correspondingly strong in order to trigger the behavior of (further) food intake in the coincidence element. If the supply condition deteriorates (again), the sensor (6) reports this to the instinct center, whereupon the motivation to eat (again) increases, whereby the external stimulus of the food "may" be correspondingly lower so that the food is attractive enough to Food intake is classified.

While even in humans one can describe behaviors for impulses such as hunger and thirst , which are related to metabolic processes in the body, but also for fatigue and “ sexual appetite ”, which fulfill the function of end actions ( eating , drinking , sleeping , sexual intercourse or masturbation ), other behaviors lock against an involvement in this model: "in response procedures, as we in the nest building in the personal care , while exploring , the battle in which flight watch this model, however, is not applicable because these behavioral consequences no behavior can be interpreted as a final act with a corresponding effect on the drive. "

The instinct theory from today's perspective

The findings of neuropsychology and brain research have made it clear since the 1970s at the latest that the control of behavior is much more complex than shown in the models by Lorenz and Hassenstein. In particular, Lorenz's drive stagnation model is now considered to be outdated, since its central basic assumption - the existence of action-specific energies - could not be verified by the methods of neurobiology : The model has “no equivalent in the organism” ( Franz Huber , 1988). Therefore, Klaus Immelmann had already warned in 1986:

“Of course, such an instinctual model from the early days of comparative behavioral research - which has often been forgotten - can really only be understood as a model . It is by no means able to give a real explanation of the underlying processes and is only intended to point out that there are higher and lower levels of behavior in terms of behavior [...]. "

The British behavioral researcher Robert Hinde made a similarly distant statement in 1988 in a commemorative publication on the occasion of Konrad Lorenz's 85th birthday about his "'psycho-hydraulic" energy model of motivation ", which Hinde was first confronted with in a lecture by Lorenz in 1950:

“I was hugely impressed by this idea. It seemed to combine so many facts about animal behavior and stimulate systematic experimentation. When it became possible for me to begin my own investigations [...] I decided to measure the dimensions of the 'reservoir' of this model. Today one can of course say that this project was naive [...]. It doesn't matter here that my results led to my discarding the model - the story led, I believe, to a better understanding of the complexity of the processes that take place when an animal is confronted with a stimulus. "

Wolfgang Wickler , a student of Konrad Lorenz, even remarked in 1990:

"The action-specific energy turned out to be a modern phlogiston and the psychohydraulic model, despite ingenious changes, was unsuitable for adequately mapping the changes in readiness and condition in the animal."

Wickler did not provide a detailed explanation, but it was provided in 1992 by the Bonn behavioral biologist and Lorenz student Hanna-Maria Zippelius . What is precarious about the theory of instinct is that there is a risk of circular conclusions : that is, if only what can be deduced from the basic assumptions of the theory is investigated and if the results are then interpreted solely in the light of the theoretical assumptions. In 1992, for example, in her book The measured theory , Zippelius drew attention to the fact that the idle action introduced by Konrad Lorenz in behavioral biology is on the one hand a direct consequence of the instinct theory, but on the other also serves to confirm it. The situation is similar with the jumping movement postulated by Lorenz and others .

In 1992/93, Zippelius' book led to a noteworthy public debate about this problem , as she had repeated various classic behavioral studies for this publication and then came to the conclusion that the work results of Lorenz (and also of Nikolaas) had a credible experimental basis Tinbergen) could not be spoken. According to their assessment, some of the results of Zippelius' studies even suggested that Lorenz and Tinbergen selectively published or omitted experimental data in order to “fit” their theory. Lorenz's aversion was also due to the fact that he defended the evolutionary concept of species conservation throughout his life .

Lorenz's instinctive theory of behavior emerged in the 1930s on the basis of relatively few and initially more anecdotally interesting animal observations. From the beginning, there was no broad empirical support for the theory, as was the case with Sigmund Freud's theories . Therefore, according to Zippelius, the instinct theory became an outstanding example of the generation of pseudo-explanations within a scientific discipline: For example, the jumping movement is a direct consequence of Lorenz's basic assumption that in the event of a conflict, the "stronger" of two simultaneously activated instincts sets itself in Conduct through; However, since the case of two equally strongly activated instincts is conceivable, a kind of compromise had to be added to the instinct theory for this special case - the jumping movement is thus more a consequence of the theory than the result of empirical findings. The very few “empirical evidence” were then quickly “discovered” or - more precisely - certain observations were appropriately interpreted in the light of the theoretical assumptions.

  • An example that is often cited, and often applied to humans, is two roosters fighting their "pecking order" and one of them suddenly pecks at the floor as if it were feeding. Against the background of instinct theory, this picking behavior can be interpreted as an expression of an equally strong instinct for aggression and flight, which causes pecking as a jumping movement. However, it can also be interpreted, for example, and much more plausibly from the point of view of behavioral ecology , as a social signal that may indicate to the rival that the pecking rooster feels so superior that it can still consume food even in this precarious situation.
  • Similarly, the idle action "discovered" by Lorenz in a hand-raised star (catching flies without a visible fly) is a consequence of the assertion that instinct energies are constantly produced by the body; Lorenz himself admitted that in 1978 when he wrote that “idle activities” are “theoretically demanding epiphenomena of the instinctual movement.” On the other hand, if the observer starts from the theoretical consideration that behavior occurs if and only if the willingness and the If a specific environmental situation is given, then he would have to “consider whether he has only incompletely described the triggering situation.” In addition, instinctual acts running into the void are (in the literal sense) “ dysteleonomic ”, i. H. their emergence is inexplicable from an evolutionary point of view: even pollution serves to dispose of overaged sperm.

Lorenz's theory of instincts has become obsolete, however, not only because of scientific-theoretical deficiencies, but mainly because modern brain research has not been able to find any physiological correlate to the assumed instincts. As a result, the research represented by Lorenz - as the Swiss science historian Tania Munz wrote in a study on the goose Martina - was “sidelined” in the “scientific climate” of the 1980s. His biographers, Klaus Taschwer and Benedikt Föger , also emphasized that Lorenz's research methods “have become rare because they are much too time-consuming before they produce results. Describing the behavioral repertoire of an animal takes years - in the research industry of the 21st century with its maxim of 'publish or perish', that is to say 'publish or lose', a sheer impossibility. "

literature

  • Daniel S. Lehrman: A Critique of Konrad Lorenz's Theory of Instinctive Behavior. In: The Quarterly Review of Biology. Volume 28, No. 4, 1953, pp. 337-363, full text (PDF) .
  • Robert Hinde : Ethological models and the concept of 'drive'. In: The British Journal for the Philosophy of Science. Volume 6, No. 24, 1956, pp. 321-331, doi: 10.1093 / bjps / VI.24.321 .
  • Robert Hinde: Energy models of motivation. In: Symposium of the Society for Experimental Biology. Volume 14, 1960, pp. 199-213. PMID 13714429 .
  • Uwe Jürgens and Detlev Ploog : From ethology to psychology. The basic concepts of comparative behavioral research using representative examples. Kindler Verlag, Munich 1974, ISBN 3-463-18124-X .
  • Theo J. Kalikow: History of Konrad Lorenz's ethological theory, 1927-1939. The role of meta-theory, theory, anomaly and new discoveries in a scientific 'evolution'. In: Studies in History and Philosophy of Science Part A. Volume 6, No. 4, 1975, pp. 331-341, doi: 10.1016 / 0039-3681 (75) 90027-8 .
  • Theodora J. Kalikow: Konrad Lorenz's ethological theory: Explanation and ideology, 1938-1943. In: Journal of the History of Biology. Volume 16, No. 1, 1983, pp. 39-72, doi: 10.1007 / BF00186675 .
  • Konrad Lorenz : Comparative behavior research. Basics of ethology. Springer, Vienna and New York 1978, ISBN 978-3-7091-3098-8 , full text (PDF) .
  • Hanna-Maria Zippelius : The measured theory. A critical examination of the instinct theory of Konrad Lorenz and behavioral research practice. Vieweg, Braunschweig and Wiesbaden 1992, ISBN 3-528-06458-7 .

See also

Individual evidence

  1. ↑ Konrad Lorenz : Comparative behavior research. Basics of ethology. Springer, Vienna and New York 1978, p. 5, ISBN 978-3-7091-3098-8 .
  2. ↑ Peter Kuenzer: The key stimulus concept of classical ethology from today's perspective. In: Gerd-Heinrich Neumann and Karl-Heinz Scharf (eds.): Behavioral biology in research and teaching. Ethology - Sociobiology - Behavioral Ecology. Aulis Verlag Deubner, Cologne 1994, pp. 36-37, ISBN 3-7614-1676-8 .
  3. ↑ Ingo Brigandt: The Instinct Concept of the Early Konrad Lorenz. In: Journal of the History of Biology. Volume 38, 2005, pp. 571-608, 2005, doi: 10.1007 / s10739-005-6544-3 , full text (PDF) .
  4. ↑ John Alcock : The behavior of animals from an evolutionary perspective. G. Fischer, Stuttgart, Jena and New York 1996, p. 24, ISBN 978-3-437-20531-6 .
  5. ↑ a b c Konrad Lorenz: Comparative behavior research. Foundations of Ethology, p. 143.
  6. ↑ Konrad Lorenz: About the concept of instinctive action. In: Folia Biotheoretica. Volume 2, No. 17, 1937, pp. 17–50, full text (PDF) .
  7. ^ Entry movement of intent in: Klaus Immelmann : Grzimeks Tierleben , supplementary volume behavior research. Kindler Verlag, Zurich 1974, p. 629.
  8. ↑ Konrad Lorenz: Comparative behavior research. Foundations of Ethology, p. 104.
  9. ↑ Bernhard Hassenstein : Behavioral Biology of the Child. 6th edition. Edition MV-Wissenschaft, Münster 2006, p. 207, ISBN 978-3-938568-51-4 . (First edition: Piper, Munich and Zurich 1973).
  10. ↑ Hanna-Maria Zippelius : The measured theory. A critical examination of the instinct theory of Konrad Lorenz and behavioral research practice. Vieweg, Braunschweig and Wiesbaden 1992, p. 239, ISBN 3-528-06458-7 .
  11. ↑ Wolfgang Schleidt (Ed.): The circle around Konrad Lorenz. Ideas, hypotheses, views. Paul Parey, Berlin and Hamburg 1988, p. 67, ISBN 3-489-63336-9 .
  12. ↑ Klaus Immelmann et al .: What is behavior. In: Funkkolleg Psychobiologie . Cover letter 1. Beltz, Weinheim 1986, p. 29.
  13. ^ Konrad Lorenz: The comparative method in studying innate behavior patterns. In: Symposia of the Society for Experimental Biology. Volume 4: Physiological mechanisms in animal behavior. Cambridge University Press, Cambridge 1950, pp. 221–268, full text (PDF)
  14. ↑ Wolfgang Schleidt (Ed.): The circle around Konrad Lorenz, p. 61.
  15. ↑ Wolfgang Wickler : From ethology to sociobiology. In: Jost Herbig , Rainer Hohlfeld (ed.): The second creation. Spirit and Demon in 20th Century Biology. Hanser, Munich 1990, p. 176, ISBN 3-446-15293-8 .
  16. ↑ Hanna-Maria Zippelius : The measured theory. A critical examination of the instinct theory of Konrad Lorenz and behavioral research practice. Vieweg, Braunschweig and Wiesbaden 1992, ISBN 3-528-06458-7 .
  17. ↑ a b Hanna-Maria Zippelius, Die measured theory, p. 71.
  18. ↑ What skip acts are actually good for. On welt.de on June 27, 2013.
  19. ↑ Konrad Lorenz: Comparative behavior research. Foundations of Ethology, p. 102.
  20. ↑ Konrad Lorenz: Comparative behavior research. Basics of Ethology, p. 5.
  21. ^ Tania Munz: "My Goose Child Martina": The Multiple Uses of Geese in the Writings of Konrad Lorenz. In: Historical Studies in the Natural Sciences. Volume 41, No. 4, 2011, pp. 405-446 [here p. 411], ISSN  1939-1811 , doi: 10.1525 / hsns.2011.41.4.405 .
  22. ^ Klaus Taschwer and Benedikt Föger : Konrad Lorenz. Biography. Zsolnay, Vienna 2003, p. 289, ISBN 3-552-05282-8 .