“All non-Jews are anti-Semitic.”

Professor of  anthropology Ashley Montagu nee Moses Israel Ehrenburg, born in 1905 to working class Jewish parent's in London's East End, he changed his name to Montague Francis Ashley-Montagu when attending (but later dropped out of) University College London in his late-teens, and when adopting U.S. citizenship in 1940, he changed it again to Ashley Montagu. Montagu attained his P.h.D. in 1936 at Colombia University under the guidance of Franz Boas, although he'd previously lied about holding an M.A., a P.h.D., and being education at Oxford and Cambridge in a 1931 letter to Harvard physical anthropologist Earnest Hooton.1

In 1942 Montagu published Man's Most Dangerous Myth: The Fallacy of Race; in 1950 he joined and became a prominent member of the United Nation Educational, Scientific and Cultural Organisation (UNESCO) after the United Nations had asked UNESCO to "consider the desirability of initiating and recommending the general adoption of disseminating scientific facts designed to remove what is generally known as racial prejudice." On July 18, 1950, UNESCO published its statement on race, a statement commonly known on the Ashley Montagu Statement, which reads: "it would be better when speaking of human races to drop the term "race" altogether and speak of ethnic groups."

In November 1992, Montagu was interviewed at length by Pat Shipman, now professor emerita of anthropology at the Pennsylvania State University, for her book The Evolution of Racism: Human Differences and the Use and Abuse of Science. 

Shipman invited Montagu to comment on the widespread criticism his UNESCO statement received from the scientific community in 1950, including that published in Man, the British journal of anthropology; its then-editor, William Fagg, had published Montagu's statement and invited comment on it from nine of Britain's leading physical anthropologists. Montagu told Shipman that he thought the critics of his statement—one of whom had been Royal Anthropological Institute—were jealous of him, and that he thought Man's editor was "a racist", adding: “If you’re brought up a Jew, you know that all non-Jews are anti-Semitic. I think it's a good working hypothesis.”Shipman noted that Montagu "believes this accounted for Fagg's behaviour."2

1. Henrika Kuklick (ed.), New History of Anthropology, Malden, MA: Blackwell Publishing, 2008, p. 245.
2. Pat Shipman, The Evolution of Racism: Human Differences and the Use and Abuse of Science, New York: Simon Schuster, 1994,  p. 166. Shipman titled the chapter of her book in which Montagu is discussed: "All Non-Jews Are Anti-Semitic".