functional theory of stratification In a classic article outlining ‘Some Principles of Stratification’ (American Sociological Review, 1945), Kingsley Davis and and Wilbert Moore
argued that unequal social and economic rewards were an ‘unconsciously evolved device’ by which societies ensured that talented individuals were supplied with the motivation to undertake training which would guarantee that important social roles were properly fulfilled. In this way, the most important functions would be performed by the most talented persons, and the greatest rewards go to those positions which required most training and were most important for maintenance of the social system.

The theory was (and remains) highly influential but has generated enormous controversy. ( M. Tumin 's Readings on Social Stratification, 1970
, offers a good selection of the classic contributions to the debate.) Davis and Moore's argument is based on the functionalist premiss that social order rests on consensual values which define collective goals that are in the general interest. In order to encourage those who are best able to realize these goals it is necessary to offer unequal rewards. Both of these propositions have allegedly been found empirically wanting. Critics have also suggested that the theory is simply an apologia for inequality. Some also maintain that it is tautological (circular), since it proposes that the occupations and other social roles which are most highly rewarded are most important to social stability, and then cites the high levels of reward as evidence of their social importance. What was lacking throughout the lengthy debate, and has yet to be found, is a criterion of ‘social importance’ that is conceptually independent of the rewards being allocated. Nevertheless, the theory continues to inform important topics of sociological discussion, including for example the literatures on social mobility and social justice. See also STATUS ATTAINMENT.