Not sure of a book to point to as a source on this idea, but I think cultures that are even in conflict for long periods of time have effects on each other and neither culture comes out the same afterward. First Peoples' had significant parts in forming North American cultures of today. For example, the Dine' have incorporated horses into their symbolic cultural heritage, and Taco Bell has enchiladas etc. It is all our, "North Americans," heritage in my view, including the influences of the Scots.