One of my students this term is from Africa. I was talking with her during a break one day, and I learned that she speaks at least four languages: French, her "mother tongue", the language of the town in which she grew up, and English. There may have been a fifth, but if so, I've forgotten.
She is not that out of the ordinary. Most of my students of the past year can speak at least two languages, not including English. If not languages, then at least two dialects of the same language. It seems the norm.
I wonder what this does to a person's perspective of the world. More than that, I wonder what it does to those culture's perspectives on the world and even their own communities. I wonder whether there has been research into whether or not there are measurable thought pattern trends in both multilingual individuals and multilingual societies. If there are measurable trends, I wonder what they might be.
Can anyone suggest any reading?