Instincts

INSTINCTS (Latin instinctum from instingue-re, instigare to incite), a concept used to designate certain types of animal and human behavior, which still lacks a unified interpretation. Generally speaking, an instinct is usually called the sum of biological reactions, hereditary, having crucially important vital significance for the individual or the genus, although the ultimate goal of the said actions is not the object of clear consciousness (building a nest, chasing prey, defensive movements, etc.). I. Historical significance of the question of instincts. The history of the doctrine of animal and human instincts is at the same time the history of psychology and the point of closest contact between psychology and natural science (Ziegler). The question of whether animals possess a reason similar to human reason or manage with the help of instincts has been discussed with unflagging interest since the time of Plato. Pythagoras, as is well known, did not yet distinguish the mental faculties of animals from those of man and, in connection with this, even admitted the transmigration of the soul from the body of animals into the human body. Aristotle, defending the rights of human reason, gave a rather complete, but very artificial scheme, according to which the soul is divided into the sensitive (characteristic also of animals) and the rational (the prerogative of a free man) and a number of other "souls" (nutritive, motive). The Stoics, who introduced the very word instinct into the psychological lexicon, wanted to designate by it that animals sometimes in their manifestations of sensory rationality reveal such a high perfection that they even seem to stand above man. Note that A. Bergson tries nowadays to place instinctive abilities above rational abilities on the grounds that instinct allegedly never errs. In the Middle Ages, the doctrine of the mysterious purposiveness of animal instincts served as one of the sources of all kinds of beliefs. Even domestic animals (cat, dog), having become the emblem of the devil, were frequently burned at the stake along with their owners, "sorcerers," to the glory of the Inquisition. Thomas Aquinas attributed to animals only the capacity for sensory desire, but denied them mind and free will. At the threshold of modern times, Descartes, not without the influence of the classical doctrine of instincts, proclaimed animals "untainted by spiritual substance" and consequently automata, and pointed to the main mechanism of action of the nervous automaton, the reflex. This assertion had an undoubted positive consequence, since it was permissible to study "automata" by methods common to all natural sciences, which was done by the works of Haller, Bell, and others. Charles Darwin linked the doctrine of instincts with the phenomena of emotions ("expression of the emotions"). He provided examples of deep analysis of certain instincts and thus paved the way for the experimental study of instincts. Although Darwin did not give a finished definition of instinct anywhere, he considered it proven that instinctive actions in their mechanism are similar to habitual ones. Spencer considered instinctive actions to be complex reflexes, which differ from ordinary reflexes only in that in instinct a combination of excitations is followed by a combination of movements. Karl Marx characterized the difference between the activity of socially living animals (bees), the "industry" of spiders, and human activity in the following words: "The spider carries out operations that resemble those of a weaver, and the bee by the construction of its wax cells puts to shame many a human architect. But not even the worst architect differs from the best bee in that, before building a cell from wax, he has already built it in his head." II. Biological significance and origin of instincts. The interpretations of instinct given above consist of various combinations of several unquestionably biological components or concepts. Authors note 1) the complexity of instinct as acts of behavior, 2) the constancy (inertia) of the manifestations of instinct, 3) the impersonality of instinct, 4) the infallibility of instinct, 5) the strictly hereditary nature of instinct. To these are added the following components of a more controversial nature: a) unconsciousness, b) purposiveness of instinct. Essentially, only one of these characteristics (the complexity of instinct) meets no objections from a modern biological point of view, although it does not exhaust the entire content. No less a figure than Charles Darwin showed that instincts are capable of changing under the influence of the same factors as bodily structure features, i.e., under the influence of the factors of the struggle for existence, natural and artificial selection, and that for this, as for the emergence of any new structural features, long periods of time are required (an example is the analysis of the instincts of domestic mammals and birds compared to wild species). Studies of bird migrations show that the path of bird migration does not represent a single line, but a wide "front," sometimes 300-400 km, and that within this front a wide individualization of the manifestation of this instinct is possible (comparison of extreme variants). The same applies to the time of departure of birds on their journey (Deryugin). In addition, it has been proven that older birds tolerate migration more easily (the influence of individual experience). A tremendous merit of Charles Darwin is the discovery of a large number of clearly infallible [sic, meaning fallible] instincts [movements of burying food scraps by domestic dogs on the smooth floor of a room, continuation of instinct-driven actions once begun (despite the fact that a change in situation deprived these actions of any significance for the animal), phenomena of lactation in unfertilized bitches (observations of L. Shimkevich), etc.]. One cannot disagree with the fact that instincts are hereditary (species-specific) actions; but the considerations given above are already sufficient to be convinced of the ability of instincts to significantly improve over a number of generations. Even wide fluctuations in the manifestation of various instincts (e.g., the sexual instinct of people of different races under different latitudes) speak of the extreme diversity of hereditary behavior. This is especially confirmed by experiments on influencing instincts by changing the internal secretion of the animal, as well as observations of animals in their natural state (e.g., comparison of the instinct of the axolotl's larva state, which possesses these instincts to the fullest, and the ambystoma, which lacks sexual instincts). As for the unconsciousness and purposiveness of instincts, these "definitions," used moreover in a metaphysical sense, least of all help to understand the nature of instinct, and rather hinder the establishment of a correct view of it: thus, unconsciousness is a purely negative definition; it requires establishing what animal consciousness is; all attempts made in this regard have proved unsuccessful. Purposiveness is an even more controversial feature of instinct than consciousness (see Vitalism). The purposiveness of many instincts has been refuted by a number of observations by Darwin and experiments of his followers. Some authors, following in the footsteps of Lamarck (Wundt, Semon), describe instinct as a habit fixed in offspring ("instinct-memory of the species"). However, this definition cannot be agreed with either. Charles Darwin showed how important it is methodologically to distinguish actions that depend on the very structure of the nervous system (proper instincts) from useful associated habits. Recent data (see below) show that the latter (habits) are as it were layered, built upon the former, i.e., instinctive actions, sometimes modifying them beyond recognition, but never replacing instinct, and even less becoming instinct themselves. Thus, defining instinct as a habit fixed in offspring leads only to a confusion of psychological and biological concepts and at the same time yields nothing methodologically. III. Anatomical base and mechanism of action of instincts. From all that has been said, it is clear that the former doctrine of instinct as an independent pre-psychic function has had its day; it no longer satisfies anyone. In order to assimilate the modern concept of instinct as the basic and at the same time most complex form of animal behavior, it is necessary to familiarize oneself with the following concepts of an anatomo-physiological nature, many of which were unknown to the authors of the 19th and even the early 20th centuries. A. The concept of nerve excitation and conduction in their modern aspect (experiments of Loeb, Lazarev, Koltsov). B. The concept of the nerve center as a complex system of connections in the brain, spinal and cerebral, in particular in the subcortical centers (works of I. P. Pavlov on the food center). C. The concept of the activity of the sympathetic nervous system. D. The concept of reciprocal inhibition and coordination of reflexes; the principle of the common path and the integrative functions of the nervous system in the sense of Sherrington. E. The concept of posture and movement reflexes (statokinetic) in the spirit of Magnus and his school. F. The concept of the interaction of conditioned and unconditioned reflexes, in particular chain reflexes (see below). The classical experiment with Goltz's dog, repeated by Zeleny, shows that manifestations of basic instincts are also observed in an animal deprived of the very uppermost (anterior) section of the central nervous system (the cerebral cortex). In this dog, all manifestations of instincts (hunger and other movements) are significantly more brightly expressed, especially regarding the periodicity of their onset. In addition, the adult dog without hemispheres plays, i.e., exhibits a number of movements that young animals mostly produce when interacting with each other.

At the same time, it reacts to external stimuli by baring its teeth and bristling its fur (“expressive movements” in the sense of Darwin). The experiments of Magnus and his school have proven the chain-like character of complex reflexes, in particular decomposing into their constituent parts (links) the chain of those reflexes of which the movements of a cat dropped from a height consist. A series of such movements allows the animal in a fatal manner (“instinctively”) to land on its feet. The chain of reflexes begins in this case with the stimulation of the receptor apparatus of the ear labyrinth, furthermore, signals from here go to the medulla oblongata and reflexively affect the change in tone of the cervical musculature (first link). From the neck muscles that have contracted by a certain magnitude, strictly defined stimuli in the experiment emanate, which reach a series of nerve cells located in another part of the nervous system (in the corpora quadrigemina). From here, the stimulation is again transferred by way of a reflex to the muscles of the anterior limbs of the trunk, thanks to which the latter are set into a normal position relative to the horizon (second link). At the same time, the muscles of the front half of the trunk, which have contracted to a known degree, send their signals through a series of centers of the spinal cord to the muscles of the hind limbs, which immediately after this are also set into a normal position, which usually occurs already by the end of the flight-jump (third link of the complex innate reflex). In some animals living in trees (e.g., flying squirrels) and using this method of locomotion as a usual one, a fourth link is added hereto—movements of the tail, which serves to change the direction of movement in the air. In birds, all these links achieve the highest coordination, without losing their physiological (reflex) character. According to the views of the modern physiological school, all without exception acts constituting, so to speak, the main stock of the animal's behavior, starting from comparatively simple ones (e.g., blinking, coughing, and respiratory movements), passing to more complex movements (e.g., to movements of the uterus and abdominal press during the expulsion of the fetus, to contractions and relaxations of the muscular wall of blood vessels lying at the basis of the heat dissipation mechanism) and ending with complex coordinations taking place during defense and attack, during the seizure of the female, during nest-building, and during the feeding of offspring in birds and mammals—all this is complex innate reactions constructed according to the type of the indicated chain reflex with a multitude of links. — On the basis of the totality of all indicated data, instincts should be called those complex innate (unconditioned) coordinations or reflexes of animals, strictly regular and moreover having a chain character, which ensure the organism's adaptation to its surrounding environment over a very wide radius. Such chains of reflexes or coordinations are in close dependence on the anatomical structure of the nervous system (including the sympathetic one) and on changes in the internal chemism of the entire body. Since some of these links (e.g., chemical ones) proceed latently in the organism and cannot always be detected by existing research methods, the doctrine of a “mysterious force” and the internal purposiveness of instincts could arise and strengthen. Since the final path (organs of movement and secretion) in the majority of instincts is common (“common field” in the sense of Sherrington), a constant struggle of instincts occurs, which lies at the basis of the periodic character of the majority of instincts. IV. The physiological nature of instincts stems from what was said about the biological nature of instincts (Darwin's observations on the “expression of sensations”) and the anatomical basis of instincts. If an instinct is not a metaphysical “drive,” but the result of the evolution of the species, it must be regarded as a totality of reflexes of varying complexity. The doctrine of conditioned, acquired salivary reflexes of I. P. Pavlov provides rich material for judging which connections in the animal's nervous system are acquired and which are present in a ready-made form from birth. (See Brain—methods of study.) The principal of those conclusions regarding unconditioned reflexes, or instincts, to which the physiology of higher nervous activity came parallel with the experimental development of the doctrine of higher nervous activity are the following. 1. Unconditioned reflexes, or instincts, can be contrasted with one another (e.g., alimentary versus sexual). At the same time, thanks to nervous induction, that one of the indicated reflexes is inhibited which at this moment is physiologically more weakly charged. The mutual inhibition of instincts is temporary (“dominant focus” of Ukhtomsky). The victory of any unconditioned reflex leads to the temporary inhibition of all conditioned reflexes built on the basis of the given instinct. 2. Unconditioned reflexes can be connected among themselves via the mechanism of temporary connection (“closure”). Thus, it turned out to be possible to connect a defensive reaction, or a reflex to the burning of the skin by an electric current, with the alimentary reflex. It is very easy to switch an alimentary stimulus to the sexual center. The switching leading to the formation of such “chains of reflexes” is determined by the individuality of the animal, the relative strength of the centers, and their state at the given moment; a weaker stimulus (in this case a pain stimulus) assumes the role of “conditioned” in relation to the alimentary one (experimental refutation of the constancy of manifestations of instincts). 3. The principal brain centers connected with the manifestation of one or another instinct can be charged with the aid of corresponding conditioned stimuli, just as we charge our alimentary center with small but strongly acting portions of food. 4. In some cases, conditioned, firmly elaborated reflexes are capable of inhibiting the manifestation of an unconditioned, innate reflex, or instinct (Frolov). 5. Manifestations of instincts depend on the functional type of the nervous system of the animal, which also serves to refute the former doctrine of the impersonality of instincts. 6. A more significant charge of the center of one or another instinctive movements is accompanied by a significant irradiation of stimulation throughout the entire nervous system, including the sympathetic system as well, which is likewise most closely connected with internal secretion (experiments of Cannon and Orbeli). 7. There exist a number of complex reflexes standing on the boundary of innate and acquired, for example, the orienting reflex. V. Modern methods of investigating instincts stem in turn from their physiological definition and, like all natural science methods, are based on observation or experiment. The latter form is more desirable, but not always feasible. Depending on the applied methods of recording results, methods can be divided into numerical, verbal, photographic, and cinematographic (especially willingly applied lately). According to the directions in which the investigation of instincts unfolds, one distinguishes: 1. The ontogenetic direction (investigation of instincts of young animals under natural conditions or in captivity). 2. The phylogenetic direction (observation of instincts in a series of successive generations). 3. Statistical investigation allowing the establishment of certain laws of the manifestation of instincts, in particular among the human mass (e.g., the average time of onset of sexual maturity associated with certain manifestations of the sexual instinct). 4. Clinical investigation of instincts, widely practiced at the present time; a large number of observations have been accumulated allowing the treatment of some forms of diseases as the result of the “liberation” of phylogenetically older coordinations, or instincts (Kretschmer). VI. The classification of instincts, to which great significance was formerly attached, can hardly be fully maintained at the present time. The obstacle to this is the above-indicated interactions of instincts with one another and their “overgrowth” with conditioned reflexes starting from a very early age. Still, all manifestations of innate behavior can be broken down into two large groups: a) instincts connected with the preservation of the life of the individual (“self-defensive” and alimentary), b) instincts connected with the preservation of the species (sexual, nest-building in birds, den-building in mammals, as well as all types of care for offspring). Among many natural scientists, psychologists, and physicians, there is a tendency to ascribe to instincts (i.e., innate reflexes) also social forms of behavior (“social” instinct). However, the Marxist analysis of phenomena of social life gives no grounds for such an assertion. From a physiological point of view, the roots of social life should be sought not in some special unconditioned reflex, but rather in all the indicated reflexes (sexual, alimentary, and self-defensive). Phenomena of social life and the history of the development of human society are especially closely connected with conditioned reflexes arising and strengthening in the process of using so-called instruments of production. All types of complex reflexes, or instincts, can suppress each other, replace each other, and also fold into chains. According to their external manifestations, instincts are divided into active, connected with the excitation of the activity of a number of nerve centers and their corresponding muscles (irradiation of excitation), and passive, connected seemingly with the exclusion of a number of centers—with the irradiation of inhibition (reflexes of hiding and “feigned death” in animals). VII. Modern problems of studying instincts.

Although some authors consider it necessary to abolish the term instinct altogether, it would nevertheless be more correct to retain it as the most concise designation for completely definite actions of animals, but to imbue it with strict natural-scientific content, as done above. One should not think that with the establishment of the aforementioned approach to instinctive activity the entire problem of instincts becomes solved; yet, thanks to the new view, the very formulation of the problem is ordered, and particular problems of instinct take their place alongside other natural-scientific problems. It still remains to be experimentally clarified: 1. Can a conditioned reflex, when repeated in generations in combination with some unconditioned reflex, become a releaser of a reaction upon its first application (whether the inheritance of acquired functional changes exists). Modern genetics answers this negatively. However, this negative conclusion is based chiefly on studies of the transmission of morphological traits. Here, however, we are dealing with the function of the advance organ (the central nervous system), which is most sensitive to all changes in the external environment. Pending experimental verification of the question, one should refrain from a final judgment. 2. What is the relationship between the function performed by a given group of nerve cells and the cell shape and their internal structure. This includes all questions of functional architectonics (O. and C. Vogt). The question still awaits its resolution. Methods of micrurgy can render great assistance here. 3. What is the relation of the chemistry of hormones to the chemistry of the most important nerve centers regulating instinctive behavior. From the establishment of these relationships, the doctrine of the biological foundations of individuality, as yet barely outlined (W. and E. Jaensch, Belov), must take its true beginning. 4. What is the relationship of the social environment, as a totality of the most complex and deliberately conditioned stimuli, to the regulators of instincts as innate forms of our behavior. It is clear that the social environment, through the emergence of instruments of production, modifies instincts, but to what degree—this question still awaits deeper analysis on an experimental basis. VIII. The practical significance of instincts for pedagogy, the clinic, and certain socio-economic disciplines is undoubtedly very great. Pedology, especially of early childhood, is unthinkable without taking instincts into account, knowledge of which constitutes, for example, the basis of the doctrine of so-called difficult childhood. No socially useful habits can be systematically consolidated without taking into account the strength and correlations of individual instincts at a given moment. The clinic, especially of nervous diseases, draws very many and valuable premises for diagnosis and therapy from the correct definition of instincts (Astvatsaturov). Parkinsonism and other forms of diseases are associated with the disorder of comparatively more elementary instincts—the movement of the body in space. Thanks to the physiological analysis of the phenomena of inhibition and switching of instincts, a path is opened to the comprehension of the mechanism of the formation of so-called complexes associated with various unconditioned reflexes, wherein the sexual instinct is stripped of the exceptional position assigned to it by Freud.