> Hence the label discourages attempts to explain
> under which historical conditions this sado-masochistic tendency
> manifests itself and under which it does not. Presumably the tendency
> would always be there, whether manifested or not.
>
Sado-masochistic character is many things, varying over historical time and from place to place. The advantage of thinking psychodynamically is in providing a conceptual way to link the personal and the social. Different types of family structure and resulting relationships in the typical course of human development result in varying types of character structure. Look at Mark Poster's CRITICAL THEORY OF THE FAMILY, which is scanned onto his website.
By the way, in response to your earlier post, the ego is not an imagined "homunculus," a term originating from a pre-scientific notion of human reproduction. It is a way of designating a group of behaviors, feelings, thought processes, mental capacities, and other things. It is a kind of shorthand way to discuss, rather systematically, a chunk of human experience. Character also is not conceived as a thing, rather, as a description of this or that type of ego. Ego structures are historically variable.
Christopher Rhoades Dÿkema