If you're a minority group of which there is a common belief (e.g. Indigenous Peoples are drunks), then if that group is part of the culture, they may believe that for themselves.
Like a catholic homosexual that hates himself.
These are systemic racism, sexualism, etc.
That culture will be embedded in policies and laws. In education and media.
If you believe you are not capable of creating change, you will not try
Stop believing what is not good for you.
You can decide what you believe in