How do stereotypes affect lives?

I'm taking a stereotype to mean: the 'common impression of a type of person based on what the majority believe / expect'.

This comes from social conditioning (both from larger social sources of films, advertising, media, etc, and smaller ones, family beliefs, school, etc).

Social conditioning forms neuron pathways in our brains, built up over time.

When faced with a familiar stereotype, these pathways are triggered and the majority of our thoughts follow those conditioned pathways.

Also, all thinking causes chemicals to be released into the body, so as to allow us to 'feel' what we think.

Therefore we are thinking, and feeling, what we have (by social conditioning) learnt to think and feel. And so this affects how we feel about people we recognise as a particular stereotype.

One thing to add. Social conditioning categorises us; it separates us into 'this' or 'that'. The emotion Love causes the opposite. It makes us connected and unified. So when we fall in love, we do not see the category of stereotype of our beloved. If we fall out of love, it then reappears.