The popular impression that a man alters his personality when speaking another tongue is far from ill-grounded. When I speak German to Germans, I automatically shift my orientation as a social being, I spontaneously adapt myself to the atmosphere characteristic of their status, outlook prejudices. The very use of the customary formulae of politeness injects a distinct flavor into the conversation, coloring attitudes and behavior. Some of these modes of expression, to be sure, are merely meaningless formulae, but by no means all. The retention of titles, in European fashion of example, colors mutual relations, as does the free and easy American way of dropping them altogether … Language is intimately interwoven with the whole of social behavior that a bilingual, for better or worse, is bound to differ from the monoglot.
Robert H. Lowie