Social structures and structures of perception of the social world The evolutionist model that leads numerous American sociologists to see other societies as so many stages on the path toward the American society consists of projecting on the contemporary world the structure of that society : a structure that is, at the same time, synchronic -in which the hierarchy of ethnic groups maintains a complex relationship with the hierarchy of classes -and diachronic -in which immigrant groups arrived in a certain historical order. The social structure, having become a mental structure, tends to organize the perception of the social world. For Parsons or Iipset, Bellah or La Palombara, every American aspires toward the model of the {WASP} {(White} {Anglo-Saxon} Protestant) in the same way that allnations are in evolution toward American society, or, more exactly, toward the {WASP} conception of that society.