Learn a foreign language to reduce bias?

XiXiDu's comment made me realize what the really important implication of this result is: it's not that learning a foreign language is a way to improve rationality (though maybe it is); it's that if you want other people to be rational, don't speak to them in their native language.

Kind of makes me wonder whether the Sequence translations are such a good idea after all...

Anything that activates System 2 (for instance, writing questions in a difficult-to-read font) has the same effect.

As a trilingual, I would still advise against doing learning a newer language for the sole sake of gaining rationality skills. There are much better and cost-efficient ways to improve rationality besides learning a newer language, which would likely take years, or depending on the language, decades, to fully master.

To answer your question, strangely enough, now that this topic has been brought up, I do have a slight change in personality whenever I switch to a different language conversationally, although I might have to experiment further if it affects whether I am more or less rational.

Speakers of multiple languages: have you noticed a similar pattern in your own lives?

The most obvious difference to me is that I can tolerate and even enjoy some things in English that I am unable to tolerate in German. For example, when I hear certain kinds of Hip hop or gangster rap in German I am instantly disgusted. When I hear similar lyrics in English then I am merely amused.

I am also much quicker to dislike people who speak German than people who speak English. For example, if I listen to some of what American politicians say I am just amused. If people utter similar things in German then my emotional reaction is much stronger.

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.

Quoting myself on MR:

1. Does using a foreign language reduce decision-making biases?

Not too surprising. This sounds like the usual cognitive disfluency effect forcing people to shift into type-2 thinking. If they can’t solve it quickly and have to think carefully about each piece, then they’re more likely to reflect and use abstract thinking – which will usually increase normative scores.

Someone here will probably know this better than I do (unfortunately :( ), but I believe there have been a series of studies done on the interplay between language and culture within certain countries--that certain constructions within the language allow for the development of differing types of cultural standards. The example that is coming to my mind is a language like German when compared to English. In English, you tend to be able to interrupt people more often, because you know where a sentence is going (You can go fuck--), whereas in German (I believe), since verbs come at the end (you yourself can go fuck--I know this isn't how it would be set up exactly), you can't interrupt nearly as much. Perhaps there is some ground in the idea that since learning languages forces you to subconsciously accept new modes of communicating, your way of looking at rational choice changes.

Of course, there's probably also an effect of simply needing to be more rigorous in a language that's not your own. My ability to be lazy in English is in part because I've spent a lot of time in this language and feel comfortable assuming things that I probably should not be. Whereas if I began to learn Mandarin, I would have to think about everything I say and do.

I have two native languages which I speak regularly and fluently. I also understand basic Spanish, but I haven't tried thinking about bets or probabilities in that language.

I think knowing two different languages so intimately, especially because my second language, Telugu, is from an Eastern culture, helps me see how values shape vocabulary. Group thinking, applause lights, and tribal politics are more salient when I switch languages, and especially when I try to find the exact word in one language to match to an important concept in the other.

For example, in Telugu, "My son" is used as an insult on par with "Bastard" or even "Motherfucker," something I can't even explain to monolingual English speakers. The idea is that parents have absolute authority over their children, so the speaker is claiming a huge amount of status over the other person, essentially asserting the right to do anything and everything to them, as one would to property. "You're like dirt to me." "Your only value is your use to me, and you have displeased me." (Interesting parallels to "Who's your daddy?", although in the West they tend to emphasize dominance through greater skill rather than parental ownership.)

A very obvious example of tribalism: "Westerner" is used as an insult with the weight that "heretic" or "apostate" would have had 100 years ago in the West. Noticing that people in India spoke this way allowed me to notice the alarming frequency with which people in the US accuse others of being "un-American" or "un-democratic." Looking back, this was probably part of what helped me admit that vague notions of "democracy" may not be the pinnacle of human government, though Enlightenment republics have worked out better than any system so far. I don't think India achieved the peak of cultural perfection back when they codified the word "Westerner" to mean "Bad Person," and it's only a few hundred years later, so I doubt the US has achieved it, either.

Other things I've noticed: "homely" has a very positive connotation, meaning essentially this, which is considered the picture of female perfection. "I" tends to disappear when I'm speaking in Telugu; there is less need for it. "I'm sleepy" becomes "Sleep is coming"; "I'm hungry" becomes, roughly, "Hunger came/was applied to me." Saying "I feel" and "I think" is awkward. I noticed that it might enhance the Mind Projection Fallacy, although I haven't tried. (It could also encourage less selfish thinking.)

I feel a step removed from both cultures as a result of being steeped in them both, which is exactly the place I want to be as an aspiring rationalist. It's a great exercise trying to translate connotations and associations across languages.

It's not clear from this description what level of fluency is assumed.

To me the biggest benefit of knowing several languages, especially very different ones, is that it forces one to acknowledge how much of one's thinking depends of small details that would be different in another language, where things are categorized differently.

In French, we use the same word for "city" and "town"; for "politics" and "policy"; so necessarily the way we speak about those will be different. In Chinese, there are different words for brothers and sisters depending on whether they are younger or older, and for cousins depending (among others) of whether they share your surname.

It's a good habit to try to imagine what some arguments would sound like in another language; some depend on etymology and can't even be translated ("how can you call a twelve year old a teenager?"; "Well Democracy comes from the Greek ..."); some work but sound much more awkward (Germany philosophy?).

I acquired a second mother tongue at a young age (English over Mandarin), and I certainly find different courses of thought more comfortable in each language. I also have different cached thoughts stored in each language, which, although usually harmless (I have a small amount of pi and my times tables memorised exclusively in Mandarin, which makes it quite funny to watch me doing arithmetic out loud), has occasionally been the source of quite painful cognitive dissonance (this has got a lot better since LW taught me to decompartmentalise).

I also, unsurprisingly, have different senses of humour and aesthetic judgements in different languages, which makes me able to enjoy speeches, songs, poems etc. in one languages while being barely able to read translations without cringing/laughing/facepalming.

I certainly wouldn't say I'm more rational in either language though, so that's another point to support the "only if you have to concentrate" hypothesis. However, it might help me to run decisions in both languages, if not only because it forces me to re-think the idea from a slightly different angle.

I don't notice this effect, though I haven't systematically tested. Then again, the two languages I speak moderately fluently are both more or less native languages.

I suspect this effect only works in languages you're not proficient in, not necessarily with all languages you can understand other than your native language.

Would translating the questions into a foreign language as one goes through the test also help? I mean, suppose a school level introduction to rational thinking was designed, and the pupils told to translate things for themselves into a FL they study? It would be good practice for both tasks, and they might retain the habit of switching to the FL when they have to formalize real-life problems. What do you think?