I think its kind of strange, but maybe that is because in my family no one seems to know anything about our family tree prior to 1900. I've always kind of wondered why some people find their families past and heritage so important, to me it seems like it builds some sort of false sense of security. IE if they are Irish they think they will/are/should be alcoholics. Or if they are of German decent they should drive sheizewagons, drink beer with too much hops, and rust their hoods.
I guess it just goes hand in hand with the general ("modern") idea of not needing to accept full responsibility for ones actions.