Interesting new paper (anyone have a link to an ungated version). Abstract (emphasis added):
Would you make the same decisions in a foreign language as you would in your native tongue? It may be intuitive that people would make the same choices regardless of the language they are using, or that the difficulty of using a foreign language would make decisions less systematic. We discovered, however, that the opposite is true: Using a foreign language reduces decision-making biases. Four experiments show that the framing effect disappears when choices are presented in a foreign tongue. Whereas people were risk averse for gains and risk seeking for losses when choices were presented in their native tongue, they were not influenced by this framing manipulation in a foreign language. Two additional experiments show that using a foreign language reduces loss aversion, increasing the acceptance of both hypothetical and real bets with positive expected value. We propose that these effects arise because a foreign language provides greater cognitive and emotional distance than a native tongue does.
My personal experience is that I've attached different parts of my personality to my different languages. I'm currently fluent in three and passable in two others. I notice that the part of my personality I attach to a given language depends on a variety of factors, but I can have a marked impact on it by focusing on my associations while learning the language. This is particularly true when I take the language from the classroom to an an experience of immersion.
In this regard I've also noticed that languages of the same root (for me: Danish, English and German) have a tendency to invoke related frames of minds whereas new language families (French, Arabic and Polish) allow me greater freedom in what kind of thoughts are likely to occupy my mind when I use them and hence what kind of person I am in this tongue. It's worth noting that the Polish me is closer to the French me than both the Arabic and Danish parts. I suspect a likeliness in grammar and syntax to have played a role in this.
Now the funny thing is that I didn't really notice this phenomena myself. While living in France I was visited by my parents. Both my dad (who was fluent in French) and my mum (who isn't and wasn't) noticed that everything from my tone of voice, to my subject matter to the way I gestured and moved changed when I changed between languages. American friends, independently, later made remarks in the same direction.
I must admit though that I haven't tried it regarding decision making. It's definitely worth a try and as it is, I'd predict that thinking in French will help me visualise a given situation, Danish would be preferred for extracting the emotional response, English for both estimating it's likeliness of happening as well as turning the given situation into a joke whereas my Polish and Arabic are not quite yet at the same level of abstraction. I'm prone to being extremely flirtatious in Polish and my Arabic has a tendency to call on my altruistic and carefree sides.