Sociobiology

Sociobiology is a branch of biology that seeks to explain social behaviour through the processes of evolution, drawing on evidence from psychology, ethology, anthropology, zoology, evolutionary theory, archaeology, and population genetics. In the study of human society, it is closely related to evolutionary anthropology, evolutionary psychology, human behavioural ecology, and aspects of sociology. The field examines how natural selection shapes patterns of interaction within and between species, including cooperation, aggression, mating systems, and social hierarchies.

Foundations and Scope

Sociobiology investigates social behaviours such as mating strategies, territoriality, cooperative hunting, parental care, and eusociality in insects. It argues that just as natural selection has shaped physical adaptations, it has also favoured behavioural traits that enhance reproductive success. These behaviours are understood, at least in part, as inherited characteristics that contribute to the survival of genes across generations.
A widely cited example is the behaviour of dominant male lions that kill cubs they did not sire. From a sociobiological perspective, this behaviour is adaptive because it removes competitors and brings females into oestrus more rapidly, increasing the infanticidal male’s genetic contribution to subsequent generations. Behaviours that did not enhance reproductive success are viewed as less likely to persist.
E.O. Wilson described sociobiology as the extension of evolutionary and population biology principles to social organisation. The discipline assumes two central premises: first, that certain behavioural traits have a genetic component; and second, that such traits have been shaped by natural selection to address specific ecological and social challenges in the environment of evolutionary adaptation.

Historical Development

Although the term “sociobiology” appeared in scientific discussions as early as the 1940s, the field gained wide attention following E.O. Wilson’s 1975 work Sociobiology: The New Synthesis. The study of social behaviour through an evolutionary lens had antecedents in nineteenth-century thought. For example, Peter Kropotkin’s Mutual Aid argued for the evolutionary importance of cooperation, while Thomas Hobbes has been described by some philosophers as an early thinker with sociobiological insights.
The term itself was introduced by the animal behaviour geneticist John Paul Scott at a 1948 conference on genetics and social behaviour. His efforts helped establish sociobiology within academic societies such as the Ecological Society of America and the American Society of Zoology. Meanwhile, Stuart A. Altmann applied quantitative sociobiological methods to primate behaviour, while Wilson drew upon the emerging theoretical frameworks of W.D. Hamilton, Robert Trivers, George R. Price, and John Maynard Smith. These researchers emphasised kin selection, reciprocal altruism, evolutionary game theory, and inclusive fitness.
Despite methodological differences, early sociobiologists shared a commitment to naturalistic observation and evolutionary reasoning at a time when field biology was being overshadowed by molecular and laboratory sciences. Wilson’s work popularised this approach and extended its application to humans, provoking intense debate.

Controversy and Debate

The publication of Wilson’s book sparked a sustained scientific and political controversy. Critics such as Stephen Jay Gould and Richard Lewontin acknowledged genetic influences on behaviour but argued that many human traits—such as aggression or altruism—are best understood in terms of culture, environment, and social structure. They warned that sociobiology risked promoting genetic determinism and neglecting human flexibility.
Sociobiologists countered that their arguments did not deny environmental influences but sought to understand how evolved predispositions interact with learning and culture. Later developments in evolutionary psychology, behavioural ecology, and evolutionary anthropology incorporated many sociobiological principles while placing further emphasis on flexibility and developmental processes.
In 2007, D.S. Wilson and E.O. Wilson proposed a reconciliation of group selection and inclusive fitness perspectives, suggesting that selection operates at multiple levels. This contributed to reducing long-standing disagreements over the mechanisms underlying social evolution.

Evolutionary Theory and Behaviour

Sociobiology applies key evolutionary concepts to explain social behaviour. Natural selection favours behavioural strategies that enhance an individual’s reproductive success or the success of genetically related individuals. To analyse behaviour, sociobiologists often use Nikolaas Tinbergen’s four questions, which distinguish between proximate causes (mechanisms and development) and ultimate causes (evolutionary function and phylogenetic history). Ultimate explanations seek to clarify the adaptive value of a behaviour and the evolutionary processes that gave rise to it.
In humans, behavioural genetics has found heritable components in traits such as intelligence, extraversion, creativity, and aggressiveness. These findings do not negate environmental influences but suggest that genetic variation contributes substantially to behavioural differences. Some theorists argue that behaviours linked to conflict or risk-taking may have been adaptive in ancestral environments. The evolutionary neuroandrogenic theory, for example, proposes that sexual selection contributed to higher competitive and aggressive tendencies in men. Other researchers, such as Mark van Vugt, explore how intergroup competition may have shaped psychological sex differences.
Writers have extended sociobiological reasoning to cultural behaviour. Elias Canetti interpreted regimes of autocracy and practices such as slavery as reflecting deep-rooted tendencies shaped by evolutionary pressures. Although such interpretations remain controversial, they have influenced broader debates about human social organisation.

Genetic Mechanisms and Behaviour

Research on animal models illustrates the impact of genes on behaviour. Studies on mice demonstrate that mutations affecting neurotransmitter pathways can alter aggression, anxiety, and maternal care. For example, the transcription factor FEV, required for maintaining serotonin levels, influences violent behaviour and maternal responsiveness. When this gene is removed, male mice exhibit immediate aggression, and females fail to nurture their offspring.
Such work supports the idea that inherited factors shape behavioural tendencies in non-human species. Applying similar reasoning to human societies remains debated, largely due to the complexity of cultural influences and ethical considerations. Nonetheless, the principle that genes interact with environmental inputs to produce behavioural patterns is widely accepted within biology.

Contemporary Perspectives and Influence

Despite early controversies, sociobiology has become foundational in modern behavioural sciences. Edward Hagen notes that it is now embedded in biological curricula and central to research in fields such as behavioural ecology and evolutionary psychology. Major journals frequently publish sociobiological studies on insects, birds, mammals, and primates, often under the broader label of behavioural ecology.
Steven Pinker and others argue that political concerns shaped some of the early criticism of sociobiology, suggesting that fears of biological determinism overshadowed scientific evaluation. Today, while disagreements persist about specific hypotheses, the broader framework linking evolution and behaviour is widely regarded as essential to understanding animal and human social systems.