What an interesting way to put the trolley problem:
> There's a runaway trolley barreling down a railway. Further down the tracks there are five people tied up and unable to move. They will die once the trolley reaches them.
> You are stood on a footbridge with an innocent bystander. You can push him off the bridge, blocking the trolley and killing him, but saving the other 5 people. Or you can do nothing and the 5 people will die.
Because there are not two, but three solutions: you can jump off the bridge and block the trolley with your own death.
I wonder how many are going to give that answer. I can see it coming from two kinds of people: the severely depressed to the point of being suicidal, people who have reached a spiritual state of bliss and awareness to value their own life and those of the other men as equally important AND they feel they are unattached enough to let go while the other 6 men may need more time in their lives.
A possible confounding factor which leaps to mind is the notion of register: almost all language instruction is in a utilitarian register, and daily L2 use is also commonly utilitarian; indeed, emotional surprise tends to cause people to fall back* on their L1.
If we could find people who learned an L2 in an emotionally charged environment (at an orphanage? in a teenage gang?) but never subsequently used it for work or leisure in a utilitarian environment, would they show the opposite results?
* I've heard that in WWII, a standard counterintelligence ploy was to suddenly stomp on an interviewee's foot to observe if they reacted with "Ow!" or "Aua!" or "Aie!", etc. (this reaction is trainable, of course, as the number of french who say "punaise" [minced, like "gosh darn"] when they hit their thumbs with a hammer will attest)
It's always been interesting to me which language we pick in which situation.
As a foreign-born immigrant in the country where I live, I've learned the local language as a teenager.
Yesterday, while talking to my mother in my mother tongue, I hit my toe and reacted in the local language. I'd say I do most of my thinking in the local language or in English, although I've only ever visited English-speaking countries as a short-term tourist. Yet, when I need to count things, like the reps when lifting weights, I'll do it in my mother tongue.
If the difference is making the answer in a language that is not the native one (even if well understood enough) maybe more than language it is about getting closer to the second system than the first one, thinking slow and in a more rational way instead of a fast instinctive/long learned patterns one.
Some languages may have some implicit culture and ways to see some things (there was some TED talk several years ago that sustained that people tend to have more savings depending how the language represent the future selves, or something like that), but if for this the problem is not which language, but that it not is the native one then the focus should be put elsewhere.
> Are creativity and problem solving improved in another language?
More likely the other way around I think? Anecdotally I've noticed that no matter how fluent, the things everyone does in their native language are counting money, swearing when they think they're alone, and a secret third thing.
I lived for many years in another country not as an expat but fully integrated in social, family, and work ways. As fluent as an adult learner can get. When I need to sit down and really think through a difficult problem, come up with a novel solution, I do it in my native language.