Polymathy not for Anglo-Saxons

The recent death of Clement Freud occasioned a discussion in the "Broadcasting House" studio last Sunday as to whether polymaths were dying out, and whether polymathy should be encouraged. It struck me that both the expert witnesses, Susan Greenfield and Lisa Jardine, came from Jewish families, as did Clement Freud, of course. Now I know there is a Jewish cultural tradition which values breadth of knowledge, but surely you don't have to be Jewish to be a polymath? I tried to think of other scientists who had a wide knowledge of the arts, or even of other sciences. Jacob Bronowski came to mind, but he, too, fits the stereotype. Peter Medawar? - father Lebanese; Steve Jones? - Welsh. Simon Singh? - there must be a Sikh background. It seems that the common factor is not ethnicity as such, but not being English. Not appearing to be clever, or knowledgeable, is an Anglo-Saxon trait.