A US geneticist has entered the debate on “who is a Jew” with a new book arguing that Jewishness has a “biological cultural basis”.

In what has been mentioned as a challenge to Shlomo Sand’s The Invention of the Jewish People, Harry Ostrer argues in Legacy: A Genetic History of the Jewish People, that this genetic link sits alongside shared culture, tradition and belief.

Mr Ostrer, a professor at New York’s Albert Einstein College of Medicine, part of Yeshiva University, said he has found that “the Jewish people — not just Ashkenazi but north African, eastern Sephardic — are linked by an overlapping set of DNA strands.

“People have been very uncomfortable with the notion of population groups and there has been a popular view in recent years that it’s not about biology or genetics, but about culture,” he said. “And it’s about both.”
His book comes three years after Mr Sand caused controversy with his claim that Jews were a religious group without any specific ethnic link to ancient Israel.

Mr Sand labelled Mr Ostrer’s argument “one of the scandals around Jewish identity” of the modern age.
But Mr Ostrer said he wanted people “to engage in discussions about tough topics like predisposition to disease”. In his book, Mr Ostrer writes about the JFS admissions case. “The court said your Jewishness is determined by participation — my book provides a different argument,” he said. But he said there was “no single Jewish gene” for anything, whether “for intelligence, for big noses or pushiness… It’s much more nuanced.”

He said he had aimed to provide a “dispassionate view” on the subject of Jewish identity, and criticised Mr Sand for starting off “with an agenda”.

“A professor from Yeshiva University finding a biological basis for identity cannot be without an agenda,” said Mr Sand.