A similar mental map often exists in our heads. We tend to have notions of a mapped humanity, with lines cutting across people and putting them into different categories: the classes, the castes, the races, the Pole and the Jew, the Hindu and the Muslim. These categorizations serve their purposes up to a point, but they can be equally misleading; like a map with thick lines they show us general tendencies, but once we set out to know more about a chunk of our social reality, it usually turns out to be much more complex.