Any study of culture change requires comparing measurements over time but this should mean comparing like with like, which in practice can be extremely problematic. There are also problems with projecting onto past societies perceptions of social relations that are based on more recent descriptions of other cultures. Good theory grows out of good ethnography, not vice versa, but good ethnography is rooted in the degree to which the ethnographer builds trust and positive relationships with local people. This depends to a large extent on the ethnographer’s own character.