His pioneering work in the 1930s on the intelligence of white and black students in the United States and his evidence as an expert witness in Delaware were instrumental in winning the Supreme Court school segregation case Brown v. Board of Education in 1954.
There, he was influenced by Franz Boas, a German anthropologist who created the cultural anthropology doctoral program at Columbia.
[1] Klineberg's research focused greatly on race problems, minorities, immigrants, nationality, and other topics related to culture and personality.
Klineberg was a polyglot and spoke English, German, Chinese in addition to the major Romance Languages.
In 1963 Klineberg was president of the 17th International Congress of Psychology, held in Washington DC.