Yesterday at the grocery store, I overheard a young woman and a young man chatting in Spanish. Well, it was mostly in Spanish. Their conversation was liberally sprinkled with English words, phrases and even whole sentences. The woman spoke English with a mild Spanish accent; the man didn't have even a trace of a Spanish accent when he spoke English.
This neighborhood and the surrounding neighborhoods have large immigrant populations--not just Mexicans, but immigrants from all over the world. It doesn't matter where people are from. I hear bilinguals switching languages mid-conversation all the time.
I'm sure many of my readers know what I'm talking about.
My mother is a true bilingual English-Italian speaker. Both languages are her first languages. She has always been an active mid-conversation language-switcher, but only when speaking Italian.
As a child I found it amusing, but I was also curious about why she did this. I would ask her, but she could never offer a satisfactory explanation. She couldn't even tell me what language she was thinking in when she switched because she wasn't aware that she was switching until it was pointed out. Then she might say? Did I do that? Like other switchers, as I learned much later, much of her switching is determined by unconscious mental activity.
Besides asking her why she switched, I tried to understand her language-switching based on observation of when she switched. I noticed, for example, that she would often switch to English when she was frustrated with my grandmother, repeating something that she had just said in Italian. il vestito rosso... (Raising her voice) The red dress! The red dress!
This, in itself, was interesting because my grandmother was not a fluent English speaker. Perhaps reiterating a point in English forced my grandmother to slow down and think more about what was being said, but this was something that was done without any conscious calculation on my mother's part.
Much of the time, I couldn't discern any reason at all for the language switching. It seemed almost random in my mother's case. And even though my grandmother wasn't fluent in English, she would also switch, though her switching seemed to follow more discernible patterns. Most of the time she switched for repetitive emphasis or as a brief addendum at the end of a sentence. She might say: 'Mi piace il vestito rosso,' datsa what I say to dem ('I like the red dress,' that's what I said to them/him/her.) I don't know what function these switched addenda served.
What I'm calling language-switching is actually called "code-switching" by linguists. Theories have been proposed to explain different types of code-switching and rules for code-switching. It's known, for example, that code-switching isn't likely to occur if it would violate the syntactic rules of one language or the other. So it won't happen when adjectives follow nouns in one language, but precede nouns in the other language. My mother would never say, she wore that dress rosso. But she might say, she wore that dress, il vestito rosso.
Wikipedia has a discussion of more general theories to explain code-switching.
The Markedness Model, developed by Carol Myers-Scotton, is one of the more complete theories of code-switching motivations. It posits that language users are rational, and choose (speak) a language that clearly marks their rights and obligations, relative to other speakers, in the conversation and its setting. When there is no clear, unmarked language choice, speakers practice code-switching to explore possible language choices. Many sociolinguists, however, object to the Markedness Model’s postulation that language-choice is entirely rational.
I doubt that rational is the right word. Switching might be an adaptive process, but my experience says that non-rational processing is involved. It occurs unconsciously and automatically.
The Communication Accommodation Theory (CAT), developed by Howard Giles, professor of communication at the University of California, Santa Barbara, seeks to explain the cognitive reasons for code-switching, and other changes in speech, as a person seeks either to emphasize or to minimize the social differences between him- or herself and the other person(s) in conversation. Prof. Giles posits that when speakers seek approval in a social situation they are likely to converge their speech with that of the other person speaking. This can include, but is not limited to, the language of choice, accent, dialect, and para-linguistic features used in the conversation. In contrast to convergence, speakers might also engage in divergent speech, with which an individual person emphasizes the social distance between him- or herself and other speakers by using speech with linguistic features characteristic of his or her own group.
This makes more sense to me. And coming from an intersubjectivist perspective, I can see code-switching as an effect of intersubjective processes.
We think, feel and behave differently depending upon interpersonal context. This isn't to say that there aren't continuities of selfhood that we bring to all people and situations, but we do quite a bit of switching and rearranging of ourselves to connect with other people, not only at the surface level, but in deeper, more nuanced, unconscious ways. There is constant mental tuning, detuning and retuning in our social interactions. Perhaps code-switching is subset of the bilingual's interpersonal attunement activity when speaking with another bilingual.
Here's Wikipedia on the phenomenological functions of intersubjectivity:
In phenomenology, intersubjectivity performs many functions. It allows empathy, which in phenomenology involves experiencing another person as a subject rather than just as an object among objects. In so doing, one experiences oneself as seen by the Other, and the world in general as a shared world instead of one only available to oneself.[...]
Intersubjectivity also helps in the constitution of objectivity: in the experience of the world as available not only to oneself, but also to the Other, there is a bridge between the personal and the shared, the self and the Others.
So this leads me to another question having to do with Asperger's Syndrome. In AS, the capacity for intersubjective attunement--reading minds in social interactions--is impaired. If code-switching is an intersubjective attunement activity, do bilingual persons with Asperger's do less code-switching? Is their code-switching qualitatively different from other bilinguals? Might we learn more about bilingual code-switching by observing it in bilingual persons with Asperger's?