1960s

The 1960s mark the emergence of an explicit gene-centered view of Darwinian evolution: W. D. Hamilton and G. C. Williams gave clear form to an insight implicit in the work of earlier neo-Darwinian pioneers. In The Selfish Gene, this decade stands not merely as a date in the history of an idea but as the point of departure for a sustained argument about how genes, organisms, and behavior relate—and about why describing evolutionary selfishness does not prescribe human selfishness.

An idea made explicit

The gene’s-eye view had been implicit in the writings of R. A. Fisher and other pioneers of neo-Darwinism in the early 1930s. Hamilton and Williams made it explicit in the 1960s. The author regarded their insight as visionary, but considered their accounts too concise to convey its full reach. He set out to amplify and develop the view, using examples of social behavior in part to counter the group-selection assumptions he believed were common in popular accounts of Darwinism.

The project began in 1972, when power cuts caused by industrial strife interrupted the author’s laboratory research. He wrote two chapters before the blackouts ended and set the work aside, returning to it during sabbatical leave in 1975. In the meantime, the theory had been extended, notably by John Maynard Smith and Robert Trivers. The book thus grew from an idea associated with the 1960s into a later synthesis, written amid the author’s sense that new ideas were circulating widely.

Genes, bodies, and behavior

The argument treats genes as replicators whose effects become visible through the organisms they help build. A modern survival machine contains thousands of genes, and its construction is an intricate cooperative process: genes affect different parts of the body, interact with one another, and can have effects that depend on other genes and the environment. A single gene does not independently produce a whole structure or behavior. Rather, it may make a difference relative to its alleles when other conditions are held sufficiently constant.

Sexual reproduction continually mixes and reshuffles genes, making any individual body a temporary combination. The gene-centered view focuses instead on genes that can persist across successive bodies and generations. The author’s definition, following G. C. Williams, is a portion of chromosomal material that can last through enough generations to serve as a unit of natural selection. That definition is not a claim that genes are self-sufficient agents: development is an interdependent process, and the book uses gene-centered language to describe differences in survival and copying over generations.

Natural selection and the limits of the metaphor

In this account, evolutionary change occurs through differences in the survival of genes in the gene pool. A gene “for” a behavior means one that influences the development of nervous systems in ways that make that behavior more likely; it does not mean that a gene consciously chooses or single-handedly causes an action. The book illustrates the distinction with inherited hygienic behavior in honey bees. Workers in hygienic strains locate diseased grubs, uncap their cells, remove the larvae, and carry them out of the hive. Rothenbuhler’s crosses produced daughter hives with different combinations of these actions, supporting the possibility that uncapping and removal depended on separate inherited factors.

The same caution governs the book’s language of purpose. Genes are not conscious agents “trying” to propagate themselves. Such expressions are shorthand for the result of natural selection: genes whose effects tend to increase their representation in future gene pools are more likely to persist. The author extends this approach to memes, while emphasizing that the analogy is not exact: memes do not have the chromosome-and-allele arrangement that makes genetic competition distinctive. In both cases, purposive language is a metaphor, not an assertion of intention.

Evolutionary account and moral choice

The 1960s gene-centered framework supports the book’s claim that ruthless competition among genes can often contribute to selfish behavior in individual organisms, while sometimes favoring limited altruism when it advances a gene’s propagation. The author distinguishes this evolutionary explanation from moral advocacy. A society governed by universal ruthless selfishness, he argues, would be undesirable; the fact that a behavior has an evolutionary explanation does not make it morally right.

The distinction gives the argument its ethical consequence. Biological nature, in the author’s view, offers little assurance that people will cooperate generously for a common good. Humans must therefore teach generosity and altruism rather than assume these will arise automatically from their biological inheritance. The decade’s theoretical shift leads, in the book, not to resignation but to a call for conscious human resistance to the implications of genetic selfishness.