"they suppose that national social culture is something fixed and immutable and buried in our genes and somehow sewn into our folk music. It isn't."

I think I'd like to fine-tune that. I believe that there is a cultural inheritance from our past, genetically and socially - but it is also changing, as the oral tradition (I suppose in these days the electronic tradition) absorbs influences from other cultures. But I'm not keen on wholesale adoption of other cultures and rejections of one's own cultures. That I think is quite distinct from the BNP approach which insists on slavish adherence to at least the old ethnicity.

We should know who we were as well as who we are.