Evolutionary psychology | branch of psychology which investigates behaviour which has evolved

The term evolutionary psychology was coined by Michael Ghiselin in 1973; however, related theses can also be found in Charles Darwin's The Descent of Man and The Expression of Emotions in Man and Animals. As early as the mid-1980s, ideas of evolutionary psychology were widely discussed with the catchphrase of the "atomic bomb in the hands of the Neanderthal".

Despite the approaches of its predecessors, evolutionary psychology did not become a distinct and influential approach until the early 1990s, including the 1992 edited volume The Adapted Mind: Evolutionary Psychology and The Generation of Culture by Jerome Barkow, Leda Cosmides, and John Tooby. In the years that followed, evolutionary psychology was regularly the subject of popular science publications by scholars such as David Buss and Steven Pinker. Similar to cognitive neuroscience, evolutionary psychology is often understood as a central element of the increasingly biologically oriented cognitive science.

Evolution of body and behavior

Typical examples of the evolution of living things relate to physical characteristics. The genetic basis responsible for a gazelle being able to run faster will increase the animal's chances of survival, as the gazelle will be better able to escape pursuers. Consequently, it is likely that the relevant alleles will gradually become established within the gazelle population and become a common trait of gazelles. According to evolutionary psychologists, the situation is no different with regard to mental traits. For example, memory, perception, problem-solving or learning abilities should have a comparable influence on the survival chances of individuals. Evolutionary psychology thus assumes that advantageous mental characteristics - insofar as they are heritable - also prevail within a population and that cognitive abilities are consequently a product of evolutionary adaptation.

An evolutionary formation of the mind can also be argued with reference to behaviors. For example, the care and protection of offspring in many species can lead to an increased probability of survival and reproduction of the offspring and ultimately to an evolutionary advantage. The possibility that such behavioural patterns could have evolved in the course of phylogeny is therefore plausible - also in relation to humans. In humans, the corresponding behaviour is to a large extent experienced in the form of mental phenomena such as "affection" and "concern for one's own children". It is therefore obvious to try to explain the development of such emotions within the framework of an evolutionary theory.

Another basic assumption for the development of the mind through natural evolution is that mental processes are correlated with physiological processes in the brain and are caused by the activity of nerve cells - that the brain is therefore a product of a long process of adaptation. Thus, the evolutionary formation of the "building blocks" of the brain also implies the evolutionary formation of the mind.

Adaptation and environment

It is undisputed within the sciences that the human psyche is also a consequence of evolutionary processes. What is disputed, however, is to what extent the thinking and feeling of human beings is shaped by mechanisms that have evolved evolutionarily and are thus innate, and how much of this evolutionary psychologists can actually find out about the evolution of the mind. The main proponents of contemporary evolutionary psychology hold quite specific theses with respect to these questions.

The starting point of current evolutionary psychological theory is often the observation that many human behaviors do not at all ensure the reproductive and survival success of humans, and in some cases even oppose it. For example, participation in a sperm bank is a cost-saving way to increase one's reproductive success. Nevertheless, men do not usually show a strong desire to act as sperm donors. Also, from today's perspective, fear of cars would be far more meaningful than fear of snakes, disgust of alcohol would be more meaningful than disgust of saliva. Yet most people are more likely to be afraid of snakes and more likely to be disgusted by saliva. Such observations may suggest that human needs and sensibilities are not limited to concerns directly relevant to survival.

Evolutionary psychologists counter such observations through the theory of the environment of evolutionary adaptedness (EEA). They point out that humans essentially evolved during the Pleistocene epoch (i.e., a period 1.8 million to 10,000 years ago). Pleistocene humans were organized into relatively small hunter-gatherer societies. In contrast, agrarian societies have existed for only about 10,000 years, and modern industrial cultures for only a few hundred years. Evolutionary psychologists now argue that looking at human history makes it clear that the human mind is adapted to a Stone Age environment, not a modern one. Cosmides and Tooby declare in this vein, "Our modern skulls house a Stone Age mind."

Evolutionary psychologists argue that behaviors that are well adapted to a Stone Age environment are not necessarily well adapted to a modern environment. Therefore, in contemporary cultures, one can observe behaviors that are sometimes radically opposed to the reproductive and survival success of humans. At the same time, however, this consideration implies that evolutionary psychological theories on the development of cognitive traits must be oriented towards Stone Age environmental conditions.

Modularity of the mind

Evolutionary psychologists assume that the brain is composed of numerous cognitive systems, each of which is specialized in the information processing of a delimited area or class of stimuli. In evolutionary psychology, the term "module" has become accepted, so that, for example, a module for recognizing faces, a fear module, or a module for estimating spatial relations is assumed. Evolutionary psychologists postulate that these specialized modules enabled our ancestors to respond quickly and effectively to environmental challenges. For this reason, these modules were selected instead of a non-specific multi-purpose intelligence, which, according to evolutionary psychologists, works more slowly and has not prevailed evolutionarily.

Current evolutionary psychology is thus tied to a particular theory about the structure of the mind: The mind is not thought to be a general, nonspecific intellectual faculty. Rather, the mind itself is said to have a fine structure and to be composed in substantial part of cognitive mechanisms with specific tasks.

This so-called theory of the modularity of the mind goes back to nativism, developed by Noam Chomsky in connection with his theory of universal grammar. Chomsky had argued that the human language faculty (and language acquisition in particular) can only be explained by assuming innate grammatical principles according to which natural languages are organized. Cognitive scientist Jerry Fodor expanded Chomsky's approach into a general theory of the modularity of the mind. According to Fodor, there are numerous innate and evolutionary cognitive mechanisms, such as in the areas of perception and memory. These mechanisms, called "modules," are specialized to a specific input, which they analyze quickly and unconsciously. However, according to Fodor, higher cognitive functions are not organized in modules; rather, there is a central processing unit that serves the conscious and complex analysis of information.

Evolutionary psychologists go beyond Fodor in claiming that the human mind is largely modularly organized. Through adaptation, they argue, numerous innate cognitive mechanisms have evolved to perform specific tasks. In this sense, Tooby and Cosmides state: "our cognitive architecture resembles a confederation of hundreds or thousands of functionally dedicated computers (often called modules). " (German: "Our cognitive architecture resembles a confederation of hundreds or thousands of functionally dedicated computers (often called 'modules'), each with a specific function.") Consequently, the goal of evolutionary psychology is to identify these modules and clarify their origins. In the view of the prehistorian Steven Mithen, modularity in the thinking of anatomically modern humans (Homo sapiens) is characterized primarily by the fact that the modules no longer operate in strict isolation from one another, but are interconnected.

Central assumptions of contemporary evolutionary psychology are thus: There is a very large number of cognitive mechanisms (modules) that are a) innate, b) highly specialized, and c) to be explained by an adaptation process in d) a stone-age environment. With these theses, contemporary research goes beyond the general definition of evolutionary psychology (as the study of the psyche from an evolutionary perspective). Many researchers therefore also understand evolutionary psychology as a new research paradigm that places new questions, research methods, and theories at the center of psychology.

The theory of the modularity of the mind has been criticized for being empirically under-researched, and confirmation for this theory comes almost exclusively from studies with variations of the Wason Selection Task. In a series of experiments with the Wason Selection Task, evolutionary psychologists Leda Cosmides and John Tooby were the first to find that people find it significantly easier to recognize deviations from social rules as rule violations than logically similar deviations from rules that have no social connection. For example, subjects made fewer errors when asked to recognize violations of the rule "If you want to drink alcohol, you must be at least 18 years old" than when they checked the rule "A card with a vowel on one side has an even number on the back" using cards. From this, Cosmides and Tooby concluded that the human brain contains a module for detecting cheaters in social negotiation situations, and interpreted the results as evidence for modular design and against content-independent general-purpose intelligence. Critics object that Cosmides and Tooby's interpretation contains a number of logicalfallacies. For example, the variation of the Wason Selection Task used only captured one aspect of deductive logic. However, since human reasoning is based on a number of other logical systems that have not been investigated (e.g. syllogistic logic, predicate logic, modal logic, inductive logic, etc.), the result of the investigation could not be regarded as a refutation of general-purpose intelligence. It is also criticized that the rules differ fundamentally not only in their degree of abstraction but also in their logical structure and that they misrepresent actual social negotiation situations. According to Cosmides and Tooby, fraud occurs whenever someone receives a service without paying for it. In real-life interactions, this is not necessarily the case, since one does not cheat when, for example, one receives a gift. Cosmides' and Tooby's finding therefore says nothing about actual negotiations and is not evidence for a cheater detection module.

Neuroscientists cite neural plasticity as an argument against the theory of modularity. Studies show that neuronal networks change throughout a person's life in response to environmental stimuli and experiences, and raise the question of the extent to which the structure of the brain is programmed in the genes. In particular, the higher systems in the neocortex, which are responsible for complex tasks, do not reveal a modular structure in neurobiological studies.