The Eyferth study, conducted by German psychologist Klaus Eyferth, examined the IQs of white and racially-mixed children raised by single mothers in post-World War II West Germany.
[2] Eyferth's study was first published under the title Eine Untersuchung der Neger-Mischlingskinder in Westdeutschland in the journal Vita Humana in 1959.
[3] Eyferth described further results in the paper Leistungen verschiedener Gruppen von Besatzungskindern in Hamburg-Wechsler Intelligenztest für Kinder (HAWIK), which was published in the journal Archiv für die gesamte Psychologie in 1961.
[8] Sorted out by sex and race, the average scores obtained were:[9] Stressing the similarity of average IQ scores across racial groups in the Eyferth study, James Flynn, Richard E. Nisbett, Nathan Brody, and others have interpreted it as supporting the notion that IQ differences between whites and blacks observed in many other studies are mostly or wholly cultural or environmental in origin.
[10] Moreover, they have pointed out that mixed-race children may have faced prejudice growing up as a racial minority, making the similarity of results even more significant.