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 Genius evolutionary theory that portrays natural selection as acting at the level of the individual gene to the exclusion of group selection models which state that it could also act at the level of organisms or species. The book also claims Dawkins embraces an outdated and prescriptive conception of evolution that actually restricts debate rather than promoting it. The book has provoked controversy with some online commentary claiming it is another 'flea', a term used by Dawkins to describe people who have published books about him or his ideas. An article by Fern Elsdon-Baker in "New Scientist" of 19 July 2009