Kenneth and Mamie Clark conducted research with African American children and doll choices to study the effects of segregation. They found that African American children were more likely to choose a White doll over a Black doll in both northern and southern states. This led them to theorize that the children did not have a healthy concept of themselves. This was the first psychological study used in a Supreme Court case, providing support for the Browns and the NAACP in their lawsuit against the Board of Education.