It is not well known that the early founders of Zionism were devoted adherents to the racial sciences and Eugenics in particular. People like Max Nordau and Arthur Ruppin. The following article shows how this was the accepted wisdom of the Zionist movement's leadership.
For example Ruppin, in charge of land settlement for the Jewish National Fund and Jewish Agency was a devotee. He rejected most Jewish immigrants as not being the 'right human material.' Indeed this 'selectivity' was an important feature of Zionist immigration policy up to and including the years of the Nazi holocaust. Ruppin, probably the most important figure in the pre-state Zionist pantheon, as well as a founder of the Zionist 'peace' group Brit Shalom, was so enamoured of this nonsense that in 1933 he met with fellow co-thinker Professor Hans Gunther, Himmler's ideological mentor. As Tom Segev noted in 'The Seventh Million' p.19:
'George Landauer, a member of the Jewish Agency and formerly a leader of the Zionist movement in Germany, suggested to Ruppin that he travel to Jena, the famous university town that had once been home to Schiller, Begel and other great German scholars. There, Landauer said, he could meet Hans F.K. Gunther, one of the leading Nazi race theorists. Ruppin would be interested; he had himself conducted some research into the origins of the ‘Jewish race,’, looking in particular for a connection between the physical appearance and the mental characteristics of the Jews. [Arthur Ruppin, Chapters of My Life, Vol. III, Building the land and the People, 1920-1942 (Tel Aviv: Am Oved, 1968), p.223. see also Ruppin, Sociology of the Jews (Hebrew) (Warsaw: Stibel, 1931), pp. 33 ff.]