Talcott Parsons translated Weber’s use of the word “Wahlverwandtschaft” as “correlations”…but maybe a better treatment would be “elective affinities.”
In view of the tremendous confusion of interdependent inﬂuences between the material basis, the forms of social and political organization, and the ideas current in the time of the Reformation, we can only proceed by investigating whether and at what points certain correlations (Wahlverwandtschaft) between forms of religious belief and practical ethics can be worked out. At the same time we shall as far as possible clarify the manner and the general direction in which, by virtue of those relationships, the religious movements have inﬂuenced the development of material culture. Only when this has been determined with reasonable accuracy can the attempt be made to estimate to what extent the historical development of modern culture can be attributed to those religious forces and to what extent to others.
Max Weber, The Protestant Ethic and the Spirit of Capitalism (underline and parenthetical mine)
For more see Richard Herbert Howe (1978) Max Weber’s Elective Affinities: Sociology Within the Bounds of Pure Reason. American Journal of Sociology, Vol. 84, No. 2 pp. 366-385