Ecology: the biology of interaction. 6.19. (supplement) The mechanism of human behavior as a result of the evolution of the behavior mechanisms of other animals

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6.18. (Addendum) Cultural Heritage as a Mechanism for Transmitting Acquired Traits

D. Shabanov, M. Kravchenko. Ecology: Biology of Interaction Chapter 6. Human Ecology and Conservation

6.20. (Addendum) Biological Features of Humans

6.19. (supplement) The mechanism of human behavior as a result of the evolution of the behavior mechanisms of other animals We have moved only a little away from kin with hairy sides, many of our feelings are quadrupedal, and others—even with fins. Igor Guberman Modern biology regards complex organismal adaptations as the result of evolution. Mechanisms governing human behavior arise as a result of the evolution of behavior mechanisms in other animals. Unfortunately, the study of human behavior has been handed over to the humanities (“anthropologists”), who do not understand (and, in most cases, fundamentally do not want to understand) biology, and therefore treat human behavior as something essentially different from the behavior of other animals. By the way, the very formulation “other animals” is a strong negative irritant for typical humanists… The comparison of human behavior with that of other animals, focusing on their similar features, is called “biologization” in the humanitarian discourse. Analyses of “higher” forms of behavior in other animals are transferred relatively calmly (since they are considered irrelevant to humans), while the study of “lower”, innate forms of behavior in humans is (utterly unfounded) perceived as an attack on human dignity. Discussion of the continuity of human behavior mechanisms relative to those of its relatives is needed, of course, not only to enlighten humanists. As we noted earlier (see point 1.13), explaining the properties of biosystems is rooted in their prehistory. A natural‑scientific view of humans requires understanding the causes, and therefore the prehistory, of the formation of human behavior. To understand its features, it is necessary to consider the evolution of behavior in other animals. Behavior is one of the mechanisms of animal adaptation to the environment. The characteristic species‑specific body structure (its morphology), its functions (physiology) and its behavior form an integrated adaptive system. In this system, behavior is the most labile element. Animal behavior is controlled by their nervous system (and the endocrine system has a substantial influence on nervous system functioning). Mechanisms governing behavior can be arranged in a certain series according to their complexity. Using superscript indices we will show three groups into which we will distribute the elements of this series: Simple reflexes I — Instincts (control of FCD) I — — Associations (conditioned reflexes) II — Imprinting II — Memory and accounting of individual experience II — — Elementary cognitive processes III — Cognition (reasoning) III. Group I includes innate behavior mechanisms. Group II includes acquired ones. Group III mechanisms, cognitive mechanisms, are naturally also acquired, but because of the peculiarity of their mechanism (use of a mental model of reality) they deserve a special status. In this series each subsequent element requires a more complex neurological basis. Probably, during evolution the behavior forms at the beginning of the presented series appeared earlier than the later ones. However, advanced species may retain both “lower” and “higher” behavior forms. Acquired and cognitive mechanisms develop on an innate base. Simple reflexes can be governed by a reflex arc consisting of only two neurons: a sensory and a motor one (although usually there is a more or less complex system of interneurons between the input and output of the reflex arc). Simple reflexes are widespread among various animals, including humans. A classic example of a simple human reflex is the knee‑jerk reflex. The basis of behavior in many animals are instincts. The concept of instinct is very ancient. Already in the 3rd century BC the Stoic philosopher Chrysippus used it to describe animal behavior. When speaking of instincts, people usually meant innate inclinations of animals that determine their behavior. Ethology classics Konrad Lorenz and Niko Tinbergen (who, together with Karl Frisch, received the 1973 Nobel Prize for establishing the foundations of this science) regarded instinct as a species‑specific sequence of actions that is triggered under certain conditions and directed toward satisfying a particular need. “Instinct is a temporary morphostructure of an animal that regularly appears in the flow of the animal’s actions in a social situation specific to it.” K. Lorenz. Instinct is “a hierarchically organized neural mechanism that responds to certain presented and permissive impulses (external and internal) with fully coordinated, vital, species‑specific movements.” N. Tinbergen. An important characteristic of instinct, according to Lorenz and Tinbergen, is its automatism. In the typical case, an instinct represents a defined sequence of actions that is realized as a single whole. Lorenz called this sequence “hereditary coordination,” and Tinbergen – “fixed action pattern” (FAP) – often also referred to as “fixed action pattern” (FAP), which we will use further. Instinctive behavior satisfies a particular need. In a specific situation, external or internal stimuli (or releasers – signals that release the specific energy of the instinctive action) cause the corresponding need to become actualized and form a motivation that governs the animal’s behavior. Motivation triggers the corresponding FAP, the fixed action pattern. Thus, instinct is a system for controlling FAP, consisting of a mechanism for its initiation and execution. It can be represented as the following chain:  (Need + Stimulus) → Motivation → FAP. Many dog owners who keep their pets in apartments have observed dogs “burying” a treat (for example, a bone) in a corner of a room for later use. The dog chooses a secluded corner, places what it wants to hide on the floor… and then acts like a robot. It scoops up the absent soil over the treat it hides. Its movements are quite dexterous; obviously, if it were dealing with loose earth or leaf litter, it would effectively hide its stash. After mechanically performing these actions, the dog steps aside and behaves as if its “cache” is securely hidden (although it lies in plain sight). Against the backdrop of normally adequate domestic animal behavior, such actions seem ominously automatic, almost inanimate. The fact is that the situation of hiding uneaten food triggers in the dog an FAP refined over many generations of wolves that masked the remains of their prey. Once the FAP is launched, it is realized as a single whole. Instinctive behavior is a refined mechanism reproducing the action pattern that brought success to the ancestors of a given individual. However, the behavior of most animals requires another mechanism that would allow accounting for the specific features of the environment in which the individual finds itself. These are various mechanisms of innate behavior. Thus, the behavior of Hydra is governed by reflexes (e.g., contraction in response to touch) and instincts (prey capture, “somersault” locomotion, etc.). However, if a water current repeatedly contacts the Hydra’s body with a branch of an aquatic plant, the contraction reflex will be suppressed. This is a form of accounting for local experience. Conditioned reflexes (associations) were discovered by Ivan Pavlov, who received the Nobel Prize in 1904. Simple conditioned reflexes are the establishment of an association between an unconditioned and a neutral stimulus. Thus, in Pavlov’s classic experiment dogs formed a link between food and a sound signal. Complex association complexes provide dynamic stereotypes. Dynamic stereotypes differ from FAPs in that they develop on the basis of learning and therefore demonstrate vastly greater flexibility. Imprinting was discovered by K. Lorenz. It is a regular memorization of a key image that occurs at a specific stage of ontogeny. For example, a newborn bird or mammal offspring must memorize characteristic features of its mother. It is born ready to receive the appropriate image and retain it for life. In childhood this image will facilitate proper interaction with parents, later – recognition of conspecifics and potential partners. As the mechanism of individual memory becomes more complex, its possible significance increases. Two more examples follow. The road wasp Pompilus preys on spiders, including tarantulas. The female paralyzes a tarantula by delivering precise stings to the spider’s nerve centers. Then the female digs a burrow, places the spider inside, and lays an egg on it. The larva eats the spider alive, pupates, and eventually emerges from the burrow, seeking a mate for reproduction, while the females also seek new spiders. The wasp’s behavior during the spider encounter is governed by instincts. It cannot be trained by trial and error—any mistake would be fatal to the wasp. Transmitting experience through learning is also impossible, partly because a wasp never sees its parents. The spider‑fighting program is an instinct refined over many wasp generations. Remember: every mother wasp is a victor in her spider fights; all succeeded in subduing their victims and laying eggs on them, from which their offspring successfully emerged. Yet the wasp’s behavior also contains acquired elements. After killing the spider, the wasp hides it in a secluded place and digs a burrow. It returns for the spider (the wasp remembers where it hid it) and drags it to the burrow (the wasp remembers where it dug). The above is reflected in a diagram explaining the behavior‑control mechanism in most animals (Fig. 6.19.1). Simple reflexes are not shown on this diagram (they are implied but not depicted to avoid clutter). The basis of behavior is the scheme described above (Need + Stimulus) → Motivation → FAP. Behavioral adjustment taking into account local environmental features is provided by acquired behavior—associations. An organism’s behavior is a way of acting on the environment and is governed by environmental influences and internal connections. [IMG_1] Fig. 6.19.1. Mechanisms providing behavior in most animals (relatively simple behavior based primarily on innate mechanisms) The refinement of mechanisms accounting for individual experience opens the way to constructing in the mind a more‑or‑less complete model of the aspects of reality important for the animal. As with imprinting, the memory of the road wasp preserves very specific images for which it is prepared. However, several such images may exist (in a typical case the wasp sequentially immobilizes and stores several spiders in burrows). As the memory mechanism improves, the number of retained images expands and their diversity grows. Interacting with the biotopic sub‑environment, the animal creates a “map” of the territory in its mind; for successful adaptation in a biocenotic environment, it must memorize many traits characterizing representatives of other species, their habits and typical manifestations; success in a population environment may be linked to remembering individual conspecific features and interaction histories. Although acquired behavior is “more expensive” (requiring a more developed nervous system and greater energy costs for its development and functioning), it is more flexible and complex. Under certain conditions, the development of a complex nervous system capable of producing flexible acquired behavior is justified. Note: the development of acquired behavior requires an innate foundation, first and foremost the nervous system that enables such behavior! Selection that refines the capacity for developing acquired behavior forms will operate in a complex and variable environment. Narrowly specialized species will likely hone optimal individual behavior on an innate (more reliable and economical) basis. Especially conducive to behavioral complexity is the lifestyle of opportunistic species (lat. opportunus — convenient, advantageous; species whose individuals can realize different behavior forms depending on the opportunities presented by a diverse environment). The refinement of behavior in individuals of such species leads to the construction in their minds first of fragmentary, then increasingly sophisticated environmental models. For example, animals that master a particular territory memorize the locations of landmarks there and move much more confidently than in unfamiliar terrain. Depending on the complexity of their cognition, territory acquisition may involve different mechanisms. The elephant shrew (order Macroscelidea) builds a complex system of dynamic stereotypes that allow rapid movement from one landmark to another within its individual range. In elephant groups, the female leader, based on her long‑life experience, forms a representation of regional characteristics and guides migrations according to weather and group needs. In the latter case, memory of many landmarks appears linked to an internal analogue of a “map” (or GPS, a geolocation system). This case transitions to the third group of behavior mechanisms—cognitive. Animals with complex behavior, such as corvids or mammals of the order Carnivora, demonstrate what Leonid Viktorovich Krushinsky called elementary cognitive (or reasoning) processes. As the model of reality formed in an animal’s mind becomes more elaborate, the ability to predict future events based on this model emerges. An animal capable of such prediction will respond not to stimuli reflecting past events, but to predictions derived from its internal model. Consider a simple example: the ability to extrapolate. An animal is shown a bait (its typical food) through a slit in a screen. The slit is such that the bait cannot be seized through it. After the animal sees the attractive object, the bait moves left or right. If the animal can extrapolate the movement of the object of interest, it will go around the screen on the side to which the bait moved. If the animal cannot extrapolate, it will go around the screen on one side (the more convenient one, or the side from which it once obtained food). It turns out, for example, that hedgehogs cannot extrapolate the movement of objects of interest, whereas turtles can. What does the ability to extrapolate mean? The presence in the mind of a model that allows predicting the result of an invisible displacement of an object. The emergence of modeling ability in animals is not miraculous; it is a logical result of evolutionary refinement of innate behavior forms and the acquired forms that develop on their basis. Modeling the environment through mental means opens potential possibilities for further behavioral complexity. Figure 6.19.2 shows the behavior‑control mechanism in animals capable of elementary cognitive functions. This scheme results from the complication of the mechanism shown in Figure 6.19.1. Comparing them, one can see that an additional “floor” has been added to the behavior‑control mechanisms. Animals capable of complex behavior engage in diverse relationships with conspecifics. Their behavior results from adaptation not only to biotopic and biocenotic but also to intra‑population sub‑environments (see point 5.04). [IMG_2] Fig. 6.19.2. Mechanisms providing behavior in highly developed animals capable of elementary reasoning functions It is time to discuss the features of human behavior. Which of the listed mechanisms manifest in it? Simple reflexes exist in humans, but they account for a relatively small part of external manifestations. Instincts, as mechanisms controlling FAP, are absent in humans. Nevertheless, scientific tradition (including the humanities) uses the concept “instinct” to describe human behavior. The fact is that the classical interpretation of instinctive behavior by Lorenz and Tinbergen is not the only possible one. “Instincts by nature are not vague or indefinite, but represent specifically organized motivating forces that arise long before they reach consciousness and then, regardless of the degree of awareness, pursue their inherited goals. Consequently, they are very close analogues of archetypes, so close that there are serious grounds to suppose that archetypes are unconscious images of instincts, in other words, that they represent patterns of instinctive behavior.” C. G. Jung. Instincts, as innate motivations described by Carl Gustav Jung, do exist in humans. But how do Jung’s instincts differ from those of Lorenz and Tinbergen? By the absence of the final stage of their realization, the FAP. Why does the chain (Need + Stimulus) → Motivation → FAP lose its last link in humans? This final stage of instinctive behavior in humans has been reduced to give way to another, more powerful and flexible mechanism—cognition. Cognition in members of our species reaches a complexity unattainable for all other species.We form and maintain in our psyche a complex model of reality. The formation of human cognitive mechanisms also turns out to be highly unusual. Innate mechanisms of the psyche develop under the influence of a hereditary program (naturally, provided development occurs in an environment normal for the given species). Acquired behavioral mechanisms are formed on the basis of innate structures, which begin to function properly as a result of specific environmental influences. For example, imprinting is ensured by the presence of genetically determined structures in the nervous system that, at a certain moment, can extract from the flow of external signals the stimulus that will acquire exclusive significance for many instinctive programs, and retain this stimulus for life. Reason is shaped by culture, supported by a particular society. The very emergence of complex culture is a consequence of our capacity for cultural inheritance (see the previous point). Cultural environment (see point 5.04) exerts a powerful influence on the formation of an individual’s psyche.