African-American psychologist and educator Kenneth Clark, who played a leading role in the civil rights movement of the 1950s and 60s, has died at the age of 90.

Mr. Clark was born in 1914 in the Panama Canal Zone, where his father worked as an agent for a fruit company. He went on to earn a doctorate in psychology from Columbia University in 1940.

Mr. Clark prepared a key study in 1950 on the effects of racial segregation in the nation's schools. The study - which found that black children viewed themselves inferior to white children - was cited by the U.S. Supreme Court in its historic 1954 decision which declared school segregation was unconstitutional.

Some information for this report provided by AP.