Hossein Jorjani
First publication: 2026 – 08 – 02
Social phenomena have traditionally been explained through a variety of conceptual frameworks. Historians have emphasized historical contingency and institutional development; sociologists have focused on social structures and collective processes; psychologists have investigated cognition, motivation, and individual behavior; economists have analyzed incentives and resource allocation. Each of these perspectives has contributed valuable insights, yet each also captures only part of a more complex reality. No single level of explanation is sufficient to account for the full richness of human social life.
During much of the twentieth century, however, sociology and biology gradually drifted apart. Partly as a reaction against earlier forms of biological determinism, and partly because of broader philosophical and ideological developments, many sociological traditions became reluctant to engage with biological explanations of social behavior. The controversies surrounding sociobiology during the 1970s further intensified this divide. Although those controversies raised legitimate methodological questions, they also contributed to a climate in which biological explanations themselves could readily be associated with reductionism or biological determinism.
Meanwhile, the biological sciences underwent a profound transformation. Inclusive fitness theory, reciprocal altruism, behavioral ecology, evolutionary game theory, comparative studies of primates and other social animals, quantitative genetics, developmental biology, and social neuroscience collectively produced an extensive body of empirical research on cooperation, conflict, communication, hierarchy, altruism, group formation, and other forms of social behavior. These developments greatly expanded the evidence available for investigating social organization and moved considerably beyond the formulations that had dominated the original sociobiological debates.
Modern research has also expanded the dimensions along which social organization can be empirically described. Social relationships differ not only in their degree or intensity of integration, but also in their duration and stability, the persistence of group membership, the exclusivity or overlap of associations, kinship structure, group size, and patterns of cooperation. Animal societies provide particularly clear examples: associations may persist for only minutes or hours, recur seasonally, continue for substantial portions of an individual’s life, or take the form of enduring pair bonds and other long-term relationships. These dimensions need not vary together. A highly coordinated association may be temporary, while a persistent relationship need not involve equally intense interaction at all times. Forms of sociality are therefore increasingly amenable to description as positions within a multidimensional empirical space rather than merely as categories or points along a single continuum.
Multiple dimensions of description should, however, be distinguished from multiple levels of explanation. The former concern the characteristics by which a social phenomenon is described and compared; the latter concern the processes through which it arises, persists, and changes. A particular form of social organization may simultaneously possess biological, psychological, cultural, historical, economic, institutional, and political components. These are not necessarily rival explanations. They may represent different levels of a causal system whose components continuously interact.
The significance of biological research on sociality is therefore methodological rather than ideological. Demonstrating that a social phenomenon possesses a biological component does not imply that it is biologically determined, just as demonstrating historical, cultural, or economic influences does not establish that it is historically, culturally, or economically determined. Human societies are produced by interacting processes operating at several levels. The appropriate scientific question is consequently not which single level should be granted explanatory supremacy, but which processes contribute to the phenomenon under investigation, how large their contributions are, and how they interact.
This principle carries a corresponding methodological obligation for social science. In discussions of phenomena such as educational attainment, it is common to consider historical circumstances, philosophical traditions, family background, social environment, cultural expectations, institutional structures, and economic resources, while the biological characteristics of the individuals themselves remain entirely outside the analysis. Yet human beings do not cease to be biological organisms when they enter a school, a university, a workplace, or an economic institution. Individuals differ biologically as well as socially, culturally, and economically. The same consideration applies to economic attainment, occupational outcomes, patterns of cooperation, and numerous other subjects investigated by the social sciences.
To acknowledge biological variation is not to claim that educational, economic, or social outcomes are biologically determined, nor does the existence of individual biological differences establish that they explain any particular observed social difference. Their relevance, magnitude, and interaction with environmental and institutional conditions must themselves be established empirically. But biology cannot reasonably be excluded in advance while historical, psychological, cultural, social, and economic influences are admitted as legitimate objects of investigation. Exclusion is itself an explanatory decision and therefore requires justification.
Contemporary social science consequently benefits from integrating complementary levels of explanation rather than treating them as mutually exclusive alternatives. Sociology need not become biology, nor should biology replace historical, cultural, psychological, economic, or institutional analysis. Each should contribute evidence where it possesses relevant explanatory resources, and each should remain subject to the methodological standards appropriate to its claims. The challenge is not to identify a privileged level from which human social life must be explained, but to determine empirically how different levels contribute to particular phenomena and interact with one another. A genuinely multidimensional social science should therefore neither privilege biology nor leave it out.
Hossein Jorjani 