Anecdotal evidence only, but having spent some time studying in the UK and Paris, it was pretty clear the all other things being equal, Europeans tend to know more languages than their American counterparts. All of the German, French, Dutch, Swedish, Spanish etc. students in the programs I attended spoke at least 2 languages, in some cases more. I dated a German girl who spoke 4 languages. On the other hand, the American students rarely spoke anything other than English.
And I don't buy the argument that Europeans "need" to know more than their home language. That may be true for a Dane or someone from some other small country. But, a German, Frenchman or Brit could quite easily go through life without learning any other languages.
Knowing more than one language is always a good thing, IMO.
Why? APf