This study addresses the puzzle of conformity in the House of Lords; why do any peers attend regularly and usually obey their party whip? Rational choice theory struggles to explain this when you bear in mind that peers tend to be unambitious and do not rely on re-election to stay in parliament. The reasons can be found in a close study of their culture and social relationships; in particular in (a) socialisation in the Lords, (b) the social status of peers, (c) the ritualisation of debate, and (d) their relationships to their party. Each is explained in turn, as part of a dynamic interplay of social and political relations, relying on the findings of an ethnography compiled during 1998-2000. This is offered as an example of why and how such anthropological perspectives on parliament can complement the approaches of political science.