Nature versus nurture

Nature versus nurture names the controversy over how far human attributes arise from inherited influences and how far they are shaped by learning and culture. In The Selfish Gene, the distinction is not a choice between genetic control and complete freedom: genes can influence behaviour indirectly, while development, interaction, and culture complicate any claim that a trait is fixed or has a single cause.

The Debate and Its Limits

The book explicitly declines to take a settled position in the nature-versus-nurture controversy. It observes that some people regard culture as so important that genes are virtually irrelevant to understanding human nature, while others disagree. Rather than declare which account is right, it leaves the question open and frames it as a problem worth investigating: if genes really are irrelevant to modern human behaviour, it remains important to ask how recently humans became exceptional among animals; if humans are less exceptional than they suppose, the broader rule deserves study.

That refusal to settle the controversy also clarifies what kind of claim the book makes. Its account of gene selfishness describes how evolution works; it is not a moral instruction to imitate genetic competition. The author warns that a society organized around ruthless selfishness would be undesirable, and argues that generosity and altruism should be taught. Genetic inheritance, in this framing, is not a verdict about what people ought to do.

Influence Without Fixity

The book rejects the assumption that inherited traits must therefore be unchangeable. Genes may influence people towards selfish behaviour, but people are not compelled to obey that influence throughout their lives. Altruism may be harder to learn if humans are not genetically programmed for it, yet difficulty is not impossibility. Culture matters because humans are strongly shaped by influences that are learned and handed down.

This qualification is consistent with the book’s account of biological development. A gene does not single-handedly produce a complex feature or behaviour. Genes interact with one another and with the external environment; a gene described as one “for” a trait is better understood as one that tends to shift development in a particular direction when other influences are held constant. Even a familiar physical example, leg growth, depends on a cooperative web of genetic and environmental conditions rather than one isolated cause.

The same distinction applies to behaviour. Genes are described as exerting powerful but indirect influence: by shaping survival machines and nervous systems, they affect the conditions under which behaviour develops. The nervous system makes moment-to-moment decisions, and learning and simulation give it room to act in ways that are not simple, immediate executions of genetic influence. In humans, the capacity to refuse a possible reproductive course is offered as an example of how behaviour can depart from what genes would favour.

Inheritance, Interaction, and Evidence

The book’s genetic language is qualified by the complexity of inheritance itself. Modern replicators operate in groups: bodies develop through intricate cooperation among many genes, with any one gene capable of affecting different parts of the body and its effects depending on other genes. Sexual reproduction further means that an individual is a temporary combination of genes. During the formation of sperm or eggs, crossing over exchanges matching portions of paternal and maternal chromosomes, creating a patchwork rather than preserving whole parental chromosomes as intact units.

The definition of a gene used in the book reflects that complexity. It is not restricted to a single protein-coding unit; it is a portion of chromosomal material capable of lasting through enough generations to function as a unit of natural selection. This evolutionary definition does not make genes independent agents in the building of an organism. The book stresses that no single genetic or environmental factor is the sole cause of a bodily part, and uses the comparison of nitrate and wheat to show the narrower claim: with other conditions in place, one factor can make a difference without producing the whole outcome on its own.

An experiment on honeybee hygiene illustrates how a complex behaviour can nevertheless have inherited components. Some strains remove infected grubs from their cells; others do not. In W. C. Rothenbuhler’s crosses, first-generation hybrid hives showed no hygiene, but subsequent results separated the behaviour into steps: some daughter hives performed the full sequence, some none of it, and some uncapped diseased cells without removing the larvae. When the experimenter removed caps himself, some apparently non-hygienic bees then carried out the removal. The case supports a careful claim about inheritance: a behaviour can depend on distinct genetic contributions, while what is observed also depends on how those contributions combine and whether the conditions permit them to be expressed.

Culture and Kinship in Human Behaviour

Culture also shapes how people recognize and respond to kinship. Human relatedness can be estimated through family descent, but people additionally learn who their relatives are through names, formal marriages, written records, and memory. Kinship customs and rituals give family obligations and loyalties a prominent place in social life. The book distinguishes these cultural ideas of kinship from genetic relatedness rather than treating them as identical.

Rules demonstrate how learned practices can organize behaviour without requiring people to calculate an underlying biological rationale. The book notes that rules can be powerful enough to be followed even when they appear harmful to the person obeying them. It also separates the cultural history of kinship from one evolutionary account of incest taboos: it suggests that their genetic advantage is presumably connected with the harmful effects of recessive genes in inbreeding, not with altruism. The distinction matters to the wider debate because a behaviour’s social meaning and its proposed evolutionary explanation are different kinds of account.

The discussion of adoption among monkeys makes the gap between social relationship and genetic relationship especially clear. Observers may call an adopting female an aunt, although there may be no evidence that she is biologically related to the orphan. The book interprets such care as a possible misfiring of a rule that usually favours kin, while acknowledging that bereaved females have also been observed taking another female’s baby. It treats the latter case as a difficult one requiring further evidence, including the adopters’ average relatedness to the infants and the circumstances of the adoption. Across these examples, neither inherited tendencies nor cultural categories alone provide a complete account of behaviour.