[wvh]

Interesting. I speak 6 languages and actively think in 3–4 of those, and I notice slight changes in my attitudes and behaviour depending on the active language in my head. It might be interesting to experiment and find out if not just the fact that it's a foreign language matters, but also the influence of the actual choice of language.

[Aqueous]

Wow, that's amazing. Did you learn all of those languages when you were a young child or did you learn them as you were getting older? Also, are you from a country that is bordered by a lot of other countries with native languages but doesn't have a native language of its own, like Switzerland?

[emodendroket]

That's a question that's already had a lot of attention devoted to it; look up the Sapir-Whorf Hypothesis if you're interested.