Segregation Ruled Unequal, and Therefore Unconstitutional

Psychologists Kenneth and Mamie Clark, PhD, demonstrated that segregation harmed black children's self-images. Their testimony before the Supreme Court contributed to the landmark Supreme Court case that desegregated American public schools: Brown v. Board of Education of Topeka, Kan.



In their groundbreaking studies, Kenneth and Mamie Clark investigated black children's racial identification and preference. Using drawings and dolls of black and white children, these researchers asked Black preschool and elementary school children to indicate which drawing or doll they preferred and which drawing or doll looked most like them. They also asked children to color line drawings of children with the color that most closely matched their own skin color. The Clarks found that Black children often preferred the white doll and drawing, and frequently colored the line drawing of the child a shade lighter than their own skin. Samples of the children's responses illustrated that they viewed white as good and pretty, but black as bad and ugly.

Clark and Clark concluded that many Black children at the time (1939-1950) "indicate a clear-cut preference for white and some of them evidence emotional conflict when requested to indicate a color preference. It is clear that the Negro child, by the age of five is aware of the fact that to be colored in contemporary American society is a mark of inferior status. A child accepts as early as six, seven or eight the negative stereotypes about his own group."


Until 1954, public schools were racially segregated, meaning that Black and White children could be forced to attend different schools. A Supreme Court ruling from 1892, Plessy v. Ferguson, legitimized these children's "separate, but equal" educations. With the help of Clark and Clark's research findings, that illustrated the effect of prejudice and discrimination on personality development, the plaintiffs in Brown v. Board of Education were able to show that segregated schools were inherently unequal, and therefore unconstitutional.

Clark and Clark's research prompted several future studies about racial identification and preference among minority children.

Practical Application

The impact of their research is evident in the court's unanimous decision, as written by Chief Justice Earl Warren: "Segregation of white and colored children in public schools has a detrimental effect upon the colored children. The impact is greater when it has the sanction of law; for the policy of separating the races is usually interpreted as denoting the inferiority of the Negro group. A sense of inferiority affects the motivation of a child to learn. Segregation with the sanction of law, therefore, has the tendency to [retard] the educational and mental development of Negro children and to deprive them of some of the benefits they would receive in a racial[ly] integrated school system." In short, segregation failed to provide Black and White children equal protection under the law - a protection guaranteed by the 14th amendment. Segregation was therefore deemed unconstitutional. Chief Justice Warren noted Kenneth Clark as one of the "modern authorities" on which the decision was based. This acknowledgement was significant because it was the first time that psychological research was cited in a Supreme Court decision and because social science data was seen as paramount in the Court's decision.

Cited Research

Clark, K. B., & Clark, M. K. (1939). The development of consciousness of self and the emergence of racial identification in Negro preschool children. Journal of Social Psychology, 10, 591-599.

Clark, K. B., & Clark, M. K. (1939). Segregation as a factor in the racial identification of Negro pre-school children: A preliminary report. Journal of Experimental Education, 8, 161-163.

Clark, K. B. & Clark, M. K. (1940). Skin color as a factor in racial identification of Negro preschool children. The Journal of Social Psychology, 11, 159-169.

Clark, K. B. & Clark, M. K. (1950). Emotional factors in racial identification and preference in Negro children. Journal of Negro Education, 19, 341-350.

Keppel, B. (2002). Kenneth B. Clark in the Patterns of American Culture. American Psychologist, Vol. 57, No. 1, 29-37

Kluger, R. (1975). Simple justice: The history of Brown v. Board of Education and Black America's struggle for equality. New York: Random House.

American Psychological Association, May 28, 2003, Revised July 2007