Oh, yes, this is what I read before -- some historians noticed that the descendants of the Vikings are usually calm, polite, nice people.
By the way I see something similar about the descendants of the Huns -- Chuvash people (they still keep a R-Turkic language which is similar to the Hunnic language) -- mostly nice, polite people.
But it's not strange. It's normal people to adopt new behavior. For example, if your grandfather used to drink a lot, why you should follow this bad habit? You can become a person with healthier life style.