We touched on this in our last discussion, I thought it would be interesting to give it a closer look. Below are a bunch of excerpts from different internet articles that discuss aspects of this issue. As usual, we'll hash it out in the discussion :)
Does language shape how we think?
"Does your language shape how you think?" Linguists have gone back and forth on this question, explains Guy Deutscher in The New York Times. Back in 1940, an article by anthropologist Benjamin Lee Whorf floated the notion that "our mother tongue restricts what we are able to think." [This may not be true, but it still may be true that our mother tongue does affect us in what it makes us think about, for example:] English does not "habitually [oblige]" its speakers to consider gender. Its speakers "do not have to consider the sexes of neighbors, friends, teachers and a host of other persons each time they come up in a conversation, whereas speakers of some languages are obliged to do so." Likewise, English speakers do not think of chairs as masculine or feminine, although a Spanish or French speaker might. It turns out that this does have an effect:
"In recent years, various experiments have shown that grammatical genders can shape the feelings and associations of speakers toward objects around them. ... When speakers were asked to grade various objects on a range of characteristics, Spanish speakers deemed bridges, clocks and violins to have more "manly properties" like strength, but Germans tended to think of them as more slender or elegant."
Then there's the matter of color: "green and blue are distinct colors in English but are considered shades of the same color in many languages." Bizarrely, it turns out that "our brains are trained to exaggerate the distance between shades of color if these have different names in our language." Even more dramatic is the effect that language seems to have on conceptions of space. There are some languages that do not use "egocentric" directional markers, such as left, right, behind, and ahead. Instead, they say "eastward" or "northward." As a result, they "need to know where the cardinal directions are at each and every moment."
This ends up changing how the speakers of these languages think:
Indeed, speakers of geographic languages seem to have an almost-superhuman sense of orientation. Regardless of visibility conditions, regardless of whether they are in thick forest or on an open plain, whether outside or indoors or even in caves, whether stationary or moving, they have a spot-on sense of direction. They don't look at the sun and pause for a moment of calculation before they say, "There's an ant just north of your foot."
So while the old theory about mother tongues restricting one's "capacity to reason" is wrong, Deutscher concludes that it's also a mistake to suppose that everyone thinks the same way. "As a first step toward understanding one another," he writes, "we can do better than pretending we all think the same."
People haven’t usually learned each language in the same way
Significantly, most people are not symmetrically bilingual. Many have learned one language at home from parents, and another later in life, usually at school. So bilinguals usually have different strengths and weaknesses in their different languages—and they are not always best in their first language.
We process differently in a second language
When tested in a foreign language, people are less likely to fall into a cognitive trap (answering a test question with an obvious-seeming but wrong answer) than when tested in their native language. In part this is because working in a second language slows down the thinking.
Being bicultural may prime you for different associations with each language
Many bilinguals are not bicultural. But some are. And of those bicultural bilinguals, we should be little surprised that they feel different in their two languages. Experiments in psychology have shown the power of “priming”—small unnoticed factors that can affect behaviour in big ways. Asking people to tell a happy story, for example, will put them in a better mood. The choice between two languages is a huge prime. Speaking Spanish rather than English, for a bilingual and bicultural Puerto Rican in New York, might conjure feelings of family and home. Switching to English might prime the same person to think of school and work.
Language learning may involve personal transformation
Our identity may play a key role in the ability to learn a second language. As we get older new experiences begin to incorporate themselves into our conscious memory. Learning a second language as an adult may serve to make the differences between distinct periods in our lives much more salient.
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The key to successful language learning … may involve a form of personal transformation. For those that are unsuccessful it may involve an inability to let go of their old selves. However, for those who embrace their new identity it can be liberating.
Adopting a language may mean adopting aspects of a culture
Language per se does not change someone but rather, a person may adopt the particular aspects of a culture. Culture can play a very large role in people’s behavior. I was struck by how withdrawn and serious people seemed in Lisbon. I had always equated Portuguese with the openness of the Brazilian people that made me wonder if culture could eliminate introversion all together. Puzzled by the idea that someone would want to be alone all the time, a Brazilian told me that in his country an introvert would most likely hang out at a party and speak to a few people in the corner while the extrovert would be drawing attention to himself or herself in the middle of the room. Lisbon seemed serious and sedate compared to Brazil. Even the accent was less melodic. But the language was for the most part the same.
Language may just be an environment of associative cues
As I thought about it more, I realized that language might serve as a form of context that triggers certain memories. One interesting analogy comes from work with deep-sea divers. Divers often seem to forget what happened to them underwater. Follow up work on this observation has found that when divers are taught a list of words underwater they are better at recalling more of those words later underwater than they are outside water. The opposite was also true. They exhibited better memory for words learned above water when they were asked to remember outside of water. Hence, a particular context serves to elicit memories relevant to that context. In this view, memory is driven by a set of cues that elicit certain responses from us.
From a memory point of view, language and/or culture can be thought of as a set of cues that elicit certain types of memories. It is entirely plausible that when exposed to these different cues people may actually shift what they remember. But the effect of change is not specific to bilingualism. It just happens that culture and/or language is a very explicit marker of this change. So maybe everyone changes depending on the context they are experiencing at the present moment. Bilinguals, engaged by context dependent memories, might just notice it more.
Cultural cues cause behavioural shift
The same is true for bilinguals except that here the language may be different. It is the environment, the culture, and the interlocutors that cause bicultural bilinguals to change attitudes, feelings and behaviors (along with language)—and not their language as such. In essence, there does not seem to be a direct causal relationship between language and personality.
A Swiss German-French-English trilingual gives us a concluding statement that is fitting:
"When talking English, French or German to my sister, my personality does not change. However, depending on where we are, both our behaviors may adapt to certain situations we find ourselves in."