There is apparently an evolutionary reason behind ‘lookism’, the aversion to ugly people. Christoph Klebl, Professor Brock Bastian, Dr Katie Greenaway and Joshua Ju-suk Rhee of the University of Melbourne write: “We found that our psychological bias against people and things we consider ugly is tied up in a built-in human response that’s designed to alert us to objects that may contain potentially harmful diseases. This is not to say that unattractive people are actually more likely to have diseases, but that an instinct kicks-in that overrides logic.”
There is a “physiological immune system … serving as a first line of defence against disease”, though Western moderns forgot that it exists.
For example, a stranger’s body fluids – like their saliva – often makes us feel disgusted because contact with it would increase our chance to catch an infectious disease. …
The presence versus absence of disease cues (these are things like a skin lesion with or without inflammation) also mean people make a judgement about ugliness, which suggests that people do respond to the suggestion of pathogen presence. … As a result, perceived ugliness may activate the behavioural immune system, which serves a specific function – defending us from potential pathogen threat.
The Ugly Truth
There is not always a correlation between ugliness and disease, but there once was, especially in settings before modern medicine or among the poor. Perhaps the most well known cultural link between ugliness and disease was leprosy. Ugliness warned us of danger — once upon a time.
There may have been other reasons besides. Biologists have long known that animals use magnificence in appearance as an indicator for choosing their mate.
This may explain why ‘bigotry’ or prejudice seems more prevalent among the poor. The educated are very good at hiding their prejudices, possibly because they have other sources of information, like lab tests and other proxy descriptors; so they can do without. But the ghost of humanity’s psychological immune reactions still survives, especially among those who have nothing else to go by.