The Bertillon system involves criminal investigations based on the theory that human beings can be categorised as criminal by measuring their facial features.
Bertillon claimed that using his method he could even determine what sort of crime is associated with a particulate set of facial features.
Reducing someones character and personality to a persons appearance is not used in forensic since anymore. It is however still common among the population of our society.
In our everyday life we see a great number of strangers every single day. Wether that is in the coffee shop, the bus, on the street or in the store we can not possibly spend time to get to know every single person we meet. Because we are curious creatures and still want to know things about people we interact with we make assumptions about them. These assumptions are based on things like appearance, body language, clothes and language.
Especially in situations that give the individual the time to observe peacefully like in public transportation it is easy to find yourself ‘giving the people around you certain characters’.
This is partially an instinctual act that originally was to make out friends from enemies. Living in civilisation has not changed that. Some people we meet, or even just next to in the bus we like others we do not. We make the first judgement of a person by their outer appearance.