Because immigrants have always been particularly prone to repetition - it's something to do with that experience of moving from West to East or East to West or from island to island. Even when you arrive, you're still going back and forth; your children are going round and round. There's no proper term for it - original sin seems too harsh; maybe original trauma would be better.

White Teeth (ed. Vintage, 2003) - ISBN: 9781400075508