Biological reductionism experienced a huge rise in the 1960s. Numerous directions and theoretical paradigms of biological reductionism, the main ones being sociobiology and evolutionary psychology, have had a huge impact on biology, psychology, sociology, anthropology, economics, and political science. Although many directions in biological reductionism arose in the second half of the twentieth century, the basic difference between modern versions and biological reductionism widespread in the 19th and early twentieth centuries is the abandonment of racist theories and concepts. Modern biological reductionism views the species Homo sapiens as a single species with only minor genetic differences between populations, and most often, flatly rejects the category of race as a category applicable to human populations.

There are two types of theoretical and methodological sources of the modern paradigm of biological reductionism. The first type of source comes from ethology. Ethology, which is part of biology, aims to discover the innate basis of animal behavior. Ethology sees animal behavior as more instinctive rather than learned. Instincts are genetically programmed behaviors and serve to turn on the mechanisms that move the animal to act and react. Ethology was developed in Europe and became popular in the early twentieth century. A group of authors applied the principles of ethology to the analysis of human behavior in the late sixties and early seventies of the twentieth century. These authors are Robert Ardrey (The Territorial Imperative: A Personal Inquiry into the Animal Origins of Property and Nations,1966), Conrad Lorenz (On Aggression, 1966),  Desmond Morris (The Naked Ape, 1967), and Lionel Tiger and Robin Fox (The Imperial Animal, 1971). These books analyzed the biological conditioning of various forms of human behavior: aggression, territoriality, sexuality, research, nutrition, etc.

Lionel Tiger and Robin Fox tried to compile a human "biogram" or "ethogram" that would list all forms of human behavior that are genetically predisposed. "A biogram is a total repertoire of possible behaviors of a kind (Tiger, Fox, 1971). Deciphering the repertoire requires knowledge of a set of biogram rules, i.e. biogrammar. Biogrammatical rules describe the principles by which behavioral language functions and enable "behavioral literacy" Psychologist John Bowlby, biologist David Attenborough, and ethnologists Nicholas Tinbergen and Karl von Frisch also dealt with ethology in the 1960s and early 1970s. Noam Chomsky's book Linguistic Structures (1957), in which the author hypothesized the existence of a linguistic instinct that influences the formation of the linguistic structure of each language, also served as a justification for the biological determinism of even the most complex forms of human behavior.

Another type of source of modern biological reductionism is represented by the theories of four biologists - William Hamilton, George Williams, Robert Trivers, and John Maynard Smith - in the field of the relationship between genes and natural selection. In 1964, William Hamilton published two articles that explored the evolution of altruistic behavior from a genetic point of view. Hamilton, rejecting group selection, concluded that the spread of the selfless gene in the population could only occur as a result of gene transfer, not through the direct transfer of that gene of selflessness from an individual to his own offspring, but by transferring it through close relatives for whom the individual sacrifices himself. and with whom he shares the gene of selflessness. This theory became known as the theory of "group selection", while a new type of adaptive behavior was called "inclusive adaptive value", (inclusive fitness), and a mathematical model of the adoption of an altruistic gene known as "Hamilton's rule" was developed. The theory of group selection did an excellent job of explaining the evolution of insects that have sterile castes - ants, termites, and bees. Alexander Hamilton applied the theory of group selection to the evolution of altruistic behavior in social mammals.

Robert Trivers is credited with developing a theory that explains a child's tendency to attract the parents' attention to himself and to separate their attention from his own siblings because he shares fewer genes with them. Trivers also showed, using game theory and computer simulations, how reciprocal altruism can develop between genetically distant individuals and even species. Maynard Smith is credited with developing the concept of "evolutionarily stable strategy". An evolutionarily stable strategy is defined as a strategy that, if adopted by the majority of members of a population, there is no alternative strategy that would yield a higher average adaptive value to the population.

Edward O. Wilson, the creator of the term sociobiology, applied for the first time the principles of group selection developed by Hamilton in the book Insect Society (1971). Four years later Wilson publishes the now classic work Sociobiology, a New Synthesis. The title is a paraphrase of Julian Huxley's book Evolution: A Contemporary Synthesis (1943), which integrates Mendelian genetics with Darwin's theory of evolution. Wilson, following Huxley, wanted to synthesize a theory of the genetic basis of social behavior based on inclusive adaptability with ethological theories of animal behavior. Wilson defines sociobiology as a discipline that systematically studies the biological bases of overall social behavior. At the end of the book, Wilson devotes one chapter to the sociobiology of man, and in 1978 he publishes the book On Human Nature, dedicated exclusively to the sociobiological interpretation of human nature and culture.

In 1976, Biologist Richard Dawkins published the popular book The Selfish Gene in which he presented the genocentric theory of evolution. Dawkins extends Hamilton's approach and looks at all of evolution from the perspective of individual genes. He starts from the point of view that, if a gene is not reproduced, it ceases to exist, so each gene "selfishly strives" primarily to reproduce itself, not an individual or a population. That is, the genes that survived through natural selection were those that created traits or behaviors in the individual animal, which enabled the most successful reproduction of those genes. All directions of modern biological reductionism that have developed since 1976 essentially represent a synthesis of Wilson's sociobiology and Dawkins' conception of the selfish gene.

Since its inception, sociobiology has left almost no scientist indifferent, some rejected it, while others placed it on a scientific pedestal. These extremes manifested themselves across scientific branches, so geneticists, biologists, anthropologists, and sociologists sided with one or the other camp. As for anthropology, apart from those ethnologists and anthropologists who already used the methods of ethology, as Lionel Tiger and Robin Fox did, sociobiology was also accepted by Napoleon Chagnon, William Irons, Sarah Blafer Hrdy, Hillard Kaplan, Robert Boyd, John Tooby, Robin Dunbar, Chris Knight, and others. Evolutionary psychology, which essentially uses the same methods and theories developed by Wilsons and Dawkins is a popular approach in psychology championed by authors like David Barash, Leda Cosmides, Steven Pinker, and Martin Daly. The sociobiological approach and approach named „human behavioral ecology“which is also closely linked and derived from sociobiology, are used by biologists like Robert Trivers, Peter Richerson, John Alcock, and Charles J. Lumsden. Common to all these directions is that they present themselves as neo-Darwinist approaches.

Sociobiology and other related neo-Darwinist approaches also influenced many sociologists of whom most notable are: Joseph Lopreato, Walter Runciman, Stephen Sanderson, Pierre van den Berghe, Jonathan Turner, Alexandra Maryanski, Richard Machelek, and Richard Udry. 

American sociologist Josef Lopreato in the second part of his career, from the 1980s, became one of the most important advocates of the sociobiological  approach in sociology. Lopreato believes that there is great compatibility between sociobiology and some currents of classical sociological theory, especially with the theoretical approach of Wilfred Pareto. Sociobiology provides an opportunity to better understand and explain many areas: gender relations, marital and family patterns, domination and subordination relationships, reciprocity and exchange relationships, and mortality and fertility patterns. Lopreato proposes the introduction of a modified "maximization principle". This principle refers to the evolutionary strategy of all species to increase "inclusive fitness" over time, that is, the survival of those genes that gave some biological species the greatest chance of survival. In humans, culture becomes a very important mediator between biological evolution and natural selection. The emergence of the idea of ​​the soul is a by-product of the sublimation of genetic activity into moral and altruistic activity. The idea of ​​the soul, which is a type of self-deception, has enabled the emergence of altruistic behavior, without the emergence of purely altruistic genes in the human genome. Lopreato believes that mortality and fertility rates have always been very similar, throughout history, and in different societies and that this is a reflection of a genetically innate strategy that acts as a regulatory mechanism.

British sociologist Walter Runciman develops his general theoretical approach in the three-volume book A Treatise on Social Theory (1983, 1989, 1997). In the second volume of the book, subtitled Substantive Social Theory (1989), Runciman presents his theoretical approach based on the sociobiological evolutionary theory of social development and the struggle between different forms of social power. In every society, there are three sources of power: the means of production, the means of persuasion, and the means of coercion. He defines society as a set of social roles through which people try to control these three sources of power. The process of evolution of human societies is composed of competitive selection between different roles. Social roles in social and cultural evolution act analogously to how biological species (their mutual competition and selection) act in natural evolution. He gives further development of his evolutionary theory in the books The Social Animals (1998) and The Theory of Cultural and Social Selection (2009).

American sociologist Stephen Sanderson throughout his career developed an evolutionary perspective in the study of human societies, and his work represents a combination of knowledge from sociology, anthropology, history, evolutionary biology, and archeology. Sanderson presented his theoretical paradigm in several books: Social Transformations: A General Theory of Historical Development (1995), The Evolution of Human Sociality: A Darwinian Conflict Perspective (2001), World Societies: The Evolution of Human Social Life (2005), Human Nature and the Evolution of Society (2014).

Sanderson calls his theoretical paradigm the Darwinian conflict theory, and it is a theoretical synthesis of several approaches: cultural materialism developed by anthropologist Marvin Harris; rational choice theory; the Weberian conflict approach; Gerhard Lenski's ecological-evolutionary theory; Immanuel Wallerstein's world systems theory; and the sociobiology. Sanderson believes that a comprehensive evolutionary theory must have the potential to explain both standard patterns of social evolution and unique ones. He strives to develop just such a theoretical paradigm, capable of explaining the general directions of social transformation, that is, periods of development, stagnation, and decline of society. Sanderson agrees with the sociobiological assumption that many aspects of human behavior are instinctive, that is, that they are a consequence of genetic adaptation that served to increase the reproductive success of individuals. Sanderson singles out several of these, as he calls them, innate instincts, or behavioral predispositions: selfish behavior for himself or his closest relatives; high sexuality, parental instinct (stronger in women), the pursuit of economic success and high status in society, as well as the instinct to achieve goals with the least possible effort. These behavioral predispositions are not rigid and how they will manifest depends on the physical and sociocultural environment.

In all societies, there are relations of cooperation and conflict. When it is more convenient for individuals to cooperate, then cooperation prevails, while otherwise, conflicts develop. There are egalitarian relations and great cooperation in the societies of hunter-gatherers because such relations give the greatest chance to each individual to survive. With the development of agriculture and the increase of the population in societies, the selfish struggle to realize the benefit for oneself and one's relatives came to the fore, so it led to the formation of a relationship of superiority and subordination and economic exploitation. The most common forms of the relationship between superiority and subordination are based on divisions by gender, class, and ethnicity.

Marvin Harris elaborated on Marx's division of social reality into base and superstructure, and this division was taken over and further reworked by Sanderson. Sanderson introduces four levels of social reality: biostructure (human biology), ecostructure (basic type of economy and related technology), structure (economic-political base), and superstructure (patterns of mental life - beliefs, values, norms, cultural preferences). The course of causality and determination goes, in most cases, from the first to the later level. This means that the biostructure influences the formation of the ecostructure, which further influences the formation of the structure, which further shapes the superstructure. Once formed, structures and superstructures can achieve a certain level of autonomy in relation to the two previous levels.

Sanderson studied the evolutionary basis of human religiosity, as well as the social evolution of religion, and the most important work that deals with that topic is the book Religious Evolution and the Axis Age (2018). He believes that human religiosity is innate and that it is a consequence of biological adaptation. As a confirmation of his hypothesis, he makes the following statements: 1) the universal presence of shamans, that were engaged in the treatment of diseases and the provision of vital resources in societies, in lower stages of evolutionary development; 2) religion has positive effects on physical and mental health; 3) religious people have more offspring; 4) several world religions originated in the period of the first millennium BC when there was a great social rift, and these new religions brought the idea of ​​an omnipotent, good and forgiving god who offers salvation from earthly torments.

Belgian-American sociologist and anthropologist Pierre van den Berghe was one of the first representatives of the sociobiological perspective in sociology, although he used the term "biosocial perspective" before this approach became more widely known as sociobiology. He believes that human sociability is a genetic predisposition acquired during evolution. In the past, sociability has increased the chances of survival and reproduction of the human species, so genes that promote sociability have increased the genetic fitness of the species.

Human sociability functions through three mechanisms: 1) kinship selection - helping those with whom we share genes; 2) reciprocity - long-term relationships of mutual assistance and 3) coercion - a relationship between persons who are not genetically related, in which one person increases his chances of survival, at the expense of another person. Van den Berghe uses a sociobiological approach to explain many social phenomena: class solidarity, family relations, ethnicity, sexual selection, etc. However, he believes that our innate predispositions can be modified by environmental or cultural factors such as ideology or technology. In modern society, culture has extremely great power, so it can act against maximizing the genetic fitness of the species.

In his book The Ethnic Phenomenon (1981), Van den Berghe presents a theory of ethnicity, based on the organization of our mind, and supported by genetic and paleoanthropological evidence. Our mind still functions at the clan level, to give us answers to key life questions: who am I ?; who are those who belong to my group ?; who are the foreigners? Since we do not live in small clans today, our mind finds an alternative substitute for a clan in the concept of ethnic group or nation. Our mind is looking for some common characteristics - historical, cultural, biological - that will serve for ethnic identification and demarcation from other nations.

American sociologist Jonathan Turner studied the biological evolution of humans, in the period from the emergence of the first hominids to the emergence of modern humans, and how that evolution shaped different areas of human existence. The results of this research are presented in the books The Social Cage: Human Nature and the Evolution of Society (1992), On the Origin of Human Emotions (2000), On the Origin of Human Society through Natural Selection (2008), The Emergence and the Evolution of Religions: By Means of Natural Selection (2018), and The First Institutional Spheres in Human Societies: Evolution and Adaptations from Foraging to the Threshold of Modernity (2022). Some of these books were written in cooperation with Alexandra Maryanski.

Turner believes that the increase in the emotional capacity of early human ancestors enabled the creation of more stable and orderly social structures. Increased emotional capacities enabled such a change because it lead to an increase in the range and nature of interpersonal relationships and created the basis for the emergence of a moral system. When studying sociocultural evolution, the main factor that determines the level of evolutionary development is the nature of technology. Thus, he singles out the following levels of socio-cultural evolution: hunter-gatherer societies, pastoral societies, horticultural societies, agrarian societies, industrial and post-industrial societies.

Books:

Alcock, J. Animal Behavior: An Evolutionary Approach (1979).

     -     The Triumph of Sociobiology (2001);

Alexander, R. D. Darwinism and Human Affairs (1979);

Barash, D. Sociobiology and Behavior (1977).

Barkow, J. H., Cosmides L., Tobby J. The Adapted Mind (1992);

Barkow, J. H. Darwin, Sex, and Status: Biological Approaches to Mind and Culture (1989);

Boyd, R., Richarson P.J. Culture and the Evolutionary Process (1985);

Chagnon, N., and W. Irons. Evolutionary Biology and Human Social Behaviour (1979);

Dawkins, R, and Degler C. N. In Search of Human Nature (1991);

Dawkins, Richard. The Selfish Gene (1976);

     -     The Extended Phenotype (1983);

Dennett, Daniel. Darwin's Dangerous Idea (1995);

Dunbar, R. I. M., Knight C., and Powers C. The Evolution of Culture (1999);

Durham, W. Interactions of Genetic and Cultural Evolution (1982);

     -     Coevolution, Genes, Culture, and Human Diversity (1991);

Fox, R. and King B. Anthropology and Culture (2002);

Knight, C., Powers C. Watts I. The Human Symbolic Revolution: a Darwinian Account (1995);

Lewin, R. Human Evolution (1984);

Lopreato, Joseph. Human Nature and Biocultural Evolution (1984);

     -     Crisis in Sociology: The Need for Darwin (1999);

Lumsden, C. J. , Wilson E. O. Genes, Mind and Culture (1981);

Lumsden, C. L. and E. O. Wilson Promethean Fire: Reflections on the Origin of Mind (1983);

Palmer, J. A., Palmer L. K. Evolutionary Psychology: the Ultimate Origins of Human Behavior (2002);

Pinker, Steven. The Language Instinct (1994);

Richeson, P. J., Boyd R. Complex Societies: the Evolutionary Origins of a Crude Superorganism (1999);

     -      Not by Genes Alone: How Culture Transformed Human Evolution (2005);

Robinson, M. H. And Tiger L. Man and Beast Revisited (1991);

Runciman, Walter. A Treatise on Social Theory: Substantive Social Theory (1989),

     -     The Social Animals (1998);

     -     The Theory of Cultural and Social Selection (2009);

Sanderson, Stephen. Social Transformations: A General Theory of Historical Development (1995); 

     -     The Evolution of Human Sociality: A Darwinian Conflict Perspective (2001); 

     -     World Societies: The Evolution of Human Social Life (2005);

     -     Human Nature and the Evolution of Society (2014);

     -     Religious Evolution and the Axis Age (2018).

Turner, Jonathan. The Social Cage: Human Nature and the Evolution of Society (1992);

     -     On the Origin of Human Emotions (2000);

     -     On the Origin of Human Society through Natural Selection (2008);

     -     The Emergence and the Evolution of Religions: By Means of Natural Selection (2018);

     -     The First Institutional Spheres in Human Societies: Evolution and Adaptations from Foraging to the Threshold of Modernity (2022);

Van den Berghe, Pierre. Age and Sex in Human Societies: A Biosocial Perspective (1973);

     -     „Bringing Beasts Back In: Toward a Biosocial Theory of Aggression”, in American Sociological Review (1974);

     -     Man in Society: A Biosocial View (1975);

     -     Inclusive Fitness and Human Family Structure (1977);

     -     Human Family Systems: An Evolutionary View (1979);

     -     The Ethnic Phenomenon (1981);

Wilson, Edward O. Sociobiology, a New Synthesis (1975);

     -     On Human Nature (1978).