Wilson, who was born in Birmingham, Alabama, graduated in biology from the University of Alabama in 1949 and obtained his PhD from Harvard in 1955. He joined the Harvard faculty the following year, becoming professor in 1964 and curator of entomology at the Museum of Comparative Zoology in 1971.

Much of Wilson's entomological work was with ants and other social insects and was comprehensively surveyed in his massive Insect Societies (1971). He has also worked on speciation and with William Brown introduced the term ‘character displacement’ to describe the process that frequently takes place when closely related species that have previously been isolated begin to overlap in distribution. The differences that do exist between the species become exaggerated to avoid competition and hybridization.

Wilson collaborated with Robert MacArthur in developing a theory on the equilibrium of island populations from which emerged their Theory of Island Biogeography (1967). To test such ideas Wilson conducted a number of remarkable experiments with Daniel Simberloff in the Florida Keys. They selected six small mangrove clumps and made a survey of the number of insect species present. They then fumigated the islands to eliminate all the 75 insect species found. Careful monitoring over the succeeding months revealed that the islands had been recolonized by the same number of species, thus confirming the prediction that “a dynamic equilibrium number of species exists for any island.”

It was, however, with his Sociobiology (1975) that Wilson emerged as a controversial and household name. He argued that “a single strong thread does indeed run from the conduct of termite colonies and turkey brotherhoods to the social behavior of man.” Using the arguments of William Hamilton and Robert Trivers, Wilson had little difficulty in showing the deep biological and genetic control exercised over many apparently altruistic acts in insects, birds, and mammals. He also proposed plausible mechanisms to explain much of the social behavior and organization of many species. Many believe, however, that he is on very shaky ground when he extends such arguments to human social evolution. Wilson has continued to produce a large number of popular, personal, and technical works. Among these are a work on ecology, The Diversity of Life (1992); his Pulitzer prize-winning The Ants (1988, written in collaboration with B. Hölldobler); and his revealing autobiography, Naturalist (1994).