ABSTRACT
Go into a restaurant or kitchen or to any behind the scenes area and you will often see some physical similarities between people working in the same area. They might, for example, be roughly the same age or the same sex or both. They might all have little education or all be graduates or all have the same social origin. What you will notice, is that as the similarities pile up the more homogeneous the people become, the more you tend to think of them as a group and the more they may see themselves as having a common identity. It is not that physical similarity causes groups to form, it is just that they may kick the thought process in that direction.
