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,
The Selfish Gene some cases while positing selection at higher levels. Both sides agree that very favourable genes are likely to prosper and replicate if they arise and both sides agree that living in groups can be an advantage to the group members. The conflict arises in part over defining concepts: In "The Social Conquest of Earth" (2012), the entomologist E. O. Wilson contends that although the selfish-gene approach was accepted "until 2010 [when] Martin Nowak, Corina Tarnita, and I demonstrated that inclusive fitness theory, often called kin selection theory, is both mathematically and biologically incorrect." Chapter 18 of "The Social Conquest of