Culture conflict theory, derived from the pioneering work of sociologist Thorsten Sellin, emphasizes the role of culturally accepted norms of conduct in the formation of cultural groups and the conflicts which arise through their interaction. Culture conflict theory argues that the group with the most power in any society ensures that their values, traditions and behaviors, which Sellin referred to as "conduct norms", are those to which all other members of society are forced to conform, and any actions which conflict with the interests of the dominant group are identified as deviant and/or criminal in nature. Sellin's original ideas continued to be developed throughout the 20th century, most notably by George Vold in the 1950s and Austin Turk in the 1960s, and continue to influence the contemporary debate. The recent work of Gregory J. Howard, Joshua D. Freilich and Graeme R. Newman applies culture conflict theory to the issue of immigrant and minority crime around the world. According to their research, while culturally homogeneous groups experience little to no cultural conflict, as all the members share the same set of "conduct norms", culturally heterogeneous groups, such as modern industrial nations with large immigrant populations, display heightened competition between sets of cultural norms which, in turn, leads to an increase in violence and crime. Societies which have high levels of cultural diversity in their population, it is claimed, are more likely to have higher rates of violent crime.