Sociocultural evolution justify new policies such as eugenics. Most 19th-century and some 20th-century approaches aimed to provide models for the evolution of humankind as a single entity. However, most 20th-century approaches, such as multilineal evolution, focused on changes specific to individual societies. Moreover, they rejected directional change (i.e. orthogenetic, teleological or progressive change). Most archaeologists work within the framework of multilineal evolution. Other contemporary approaches to social change include neoevolutionism, sociobiology, dual inheritance theory, modernisation theory and postindustrial theory. In his seminal 1976 book "The Selfish Gene", Richard Dawkins wrote that "there are some examples of cultural evolution in birds and monkeys,
Richard Dawkins: How a Scientist Changed the Way We Think Ridley. () The reviews of the book have been mixed, but the controversial title phrase, "How a Scientist Changed the Way We Think" has been explained by considering Dawkins to have worked as an influential educator and concise author, of "The Selfish Gene", who promoted the key ideas of others about evolutionary biology, also including some controversial ideas which are not as widely accepted. As the author of a popular science book, Dawkins had popularized ideas by George Williams about group selection, William Hamilton on the theory of kin selection in evolution, biologist/geneticist John Maynard Smith on evolutionarily stable strategies,