Internalized oppression happens when people absorb negative messages about their own group from the society around them. It can show up as self-doubt, shame about one's appearance or culture, colorism, or policing others in one's group to meet the dominant group's standards.
In the 1940s, psychologists Kenneth and Mamie Clark asked Black children to choose between Black and white dolls. Many preferred the white dolls and called them nice. The Supreme Court cited the Clarks' work in Brown v. Board of Education (1954) to show the harm segregation did to Black children.
Thinkers such as Paulo Freire and Frantz Fanon described how oppressed people can come to see themselves through their oppressors' eyes. Internalized oppression is not a personal failing. It is a result of systems that teach some groups they are less than. Healing work, affirming spaces and cultural pride help counter it.