Hossein Jorjani
First publication: 2026 – 08 – 02
The emergence of sociobiology during the second half of the twentieth century represented one of the earliest systematic attempts to interpret human social behavior within an evolutionary framework. By emphasizing that human societies are products of biological evolution, it stimulated valuable dialogue between biology and the social sciences. At the same time, many of its stronger explanatory claims represented extrapolations considerably beyond the evidential support available from evolutionary biology at the time. The principal methodological difficulties arose not from the application of evolutionary theory itself, but from the premature extension of evolutionary reasoning to complex human institutions and behaviors.
One of the central assumptions of early sociobiology was that observed differences in human behavior could often be interpreted as products of natural selection. Yet such conclusions require considerably more evidence than the mere existence of behavioral or social differences.
First, modern political institutions, formal education, scientific research, engineering, bureaucratic administration, and many occupational specializations are evolutionarily recent developments. Under any realistic quantitative genetic model involving numerous loci of small effect, substantial evolutionary differentiation in predispositions toward participation in such institutions would require sustained selection acting over many generations under relatively stable environmental conditions. Such assumptions cannot simply be taken for granted.
Second, a further methodological limitation concerns the genetic architecture of complex traits. Evolution rarely acts upon isolated characteristics. Quantitative genetics has demonstrated that most traits evolve within networks of genetic correlations, pleiotropic effects, developmental constraints, and physiological trade-offs. Selection acting upon one characteristic, therefore, produces correlated evolutionary responses in many others. Consequently, adaptive explanations that focus exclusively upon a single behavioral trait, while neglecting the broader genetic covariance structure, provide only a biased account of the evolutionary process.
Third, equally important is the distinction between phenotypic and genetic variation. Demonstrating differences in behavior, occupational distribution, or social organization does not establish that genetic factors contributed to such differences; even evidence of a genetic contribution would not, by itself, establish that it arose through recent natural selection. Human behavior is simultaneously influenced by genetic, developmental, cultural, educational, economic, institutional, and historical factors. Evolutionary explanations, therefore, require direct evidence concerning heritability, selection, and genetic architecture rather than inference from phenotypic observation alone.
Fourth, to argue that contemporary sex differences in political representation or engineering reflect recent genetic evolution requires demonstrating not merely that such differences exist, but that the relevant selective pressures remained sufficiently strong and stable over enough generations to produce measurable evolutionary change.
These methodological reservations should not be interpreted as objections to evolutionary biology. On the contrary, subsequent developments in quantitative genetics, behavioral ecology, evolutionary game theory, comparative cognition, developmental biology, and social neuroscience have greatly strengthened the biological investigation of sociality. Contemporary evolutionary biology has largely moved beyond simple adaptationist narratives toward quantitative models that integrate interacting genetic, developmental, ecological, cultural, and social processes.
The stronger extrapolations of early sociobiology also had lasting consequences for the climate of scientific discussion. Many sociologists and scholars in neighboring disciplines came to associate biological explanations of human social behavior with biological determinism and, more broadly, with earlier attempts to construct sociology upon supposedly universal laws derived from the natural sciences, sometimes placing sociobiology in an intellectual lineage extending back to Comte. The resulting polarization outlived the original controversy. Although sociobiology became less prominent as a distinct program, the biological study of social behavior continued vigorously in animal behavior and behavioral ecology, while related evolutionary arguments re-entered the human sciences through fields such as evolutionary psychology and evolutionary anthropology and, more indirectly, through the widespread influence of gene-centered interpretations of evolution. The unfortunate result was therefore not the disappearance of biological explanations of sociality, but their uneven development across disciplinary boundaries: methodological overreach had encouraged suspicion of biology within parts of sociology, even as closely related evolutionary approaches continued to develop elsewhere.
The lesson is therefore methodological rather than ideological. The appropriate scientific response to the limitations of classical sociobiology is neither to reject biological explanations nor to accept them uncritically, but to formulate them according to the evidential standards of modern evolutionary biology. Only by satisfying those standards can evolutionary explanations contribute reliably to the scientific understanding of human social organization.
Hossein Jorjani 