Incest and Bestiphilia. In the old days it also included buggery.
Cornwall yes, Im sure is full of this kinf of thing, but Camborne especially so. Camborne was at the time of the Trevithick engine, one of the richest towns in the world. Jump forward 100 years and you have basically the decendents of the people who could not afford to get out when the bottom dropped out of the Tin inustry, who stayed in a basically ruined, post industrial hell hole, with no money and nothing to do. Hence turning inward....
Shit, I need to make some models of Unnatural Criminals in VSF gear dont I?