Last week the linguistics department here at Michigan hosted the 2012 Marshall M. Weinberg Symposium. The theme for this year’s symposium was bilingualism. I learned a ton from the various speakers, much of it about how hard it was to learn a second language after very early childhood.

Even people who appear, to naive judges, to be fluent in a second language they learned after childhood, perform well below native speakers at cognitively demanding linguistic tasks, such as understanding speech in noisy environments, or explaining proverbs. I don’t have the citation link for this, but J├╝rgen Meisel reported that German students learning French by immersion did much better if the immersion started between 32 and 42 months than they did if they started after 42 months. The errors that he reported were common among the older learners after several months of immersion, like not getting the genders of articles right even for words like maman where you would think it was obvious, were really striking. Karen Emmorey reported that the same thing was true for learners of ASL; late learners can become fluent enough for practical purposes, but are never as good as people who learn ASL in early childhood.

The striking contrast to all this is how successful first language acquisition is. To a first approximation, 100% of people successfully learn the syntax of their first language, and do so at a staggeringly young age.

I realised a few days after the symposium that there was a huge question I wish I’d asked. Why are we so good at learning a first language, and so poor at learning a second language. What cognitive system would have such a feature(/bug), and what evolutionary advantage could there be to having such a system?

Here’s one possible answer that I think is simple, explanatory, and sadly not consistent with the data. As Gilbert Harman noted in his talk, philosophers have long argued about the question of whether humans think in language. (Being philosophers, they’ve also argued about what the question even means, and that’s not a trivial issue.) Let’s adopt the following working hypothesis: humans who have learned a first language think in it, those who haven’t, don’t. This transition, from not thinking in language to thinking in it, runs very deep in the system. Once you have learned a language, it is impossible to not think in it. Compare the striking fact that once you learn a language, it is impossible to not interpret sounds you hear that are communications in that language. Once this transition is made, learning a language goes from being an instinctive task to a cognitive task. In Kahneman’s terms, it goes from being a system 1 task to a system 2 task. And learning a language is just too hard a task for system 2; it is literally harder than rocket science or brain surgery.

This obviously can’t be the complete story; a full explanation would need to fill in a lot of gaps. And the analogy I appeal to with Kahneman’s system 1/system 2 can’t be completely right. In Kahneman’s examples, system 2 is supposed to be more accurate than system 1, but self-consciously learning a language ends up being less accurate. The bigger problem, however, is that the hypothesis gets the timing all wrong.

The Meisel studies I mentioned do say that learning a language gets harder after about 42 months. They don’t say it gets harder after 24 months, let alone after 36 months. In fact, the students who start second language immersion then seem to do pretty well. But my little hypothesis would predict they’ll do badly, since by those ages they do speak their first language.

There’s also a problem at the other end. Profoundly deaf children with hearing parents often don’t learn a sign language until very late. And since they are deaf, they don’t learn a spoken language either. But that doesn’t mean their minds retain the plasticity to adopt a new language as a native speaker. Instead (at least according to results Karen Emmorey mentioned in Q&A), they do worse than even second language learners of ASL.

So I don’t have much of a theory as to why we should be wired this way. I assume that something in the ballpark of my hypothesis is right. Our ability to learn language isn’t switched off, it is inhibited by some other abilities we acquire. But how that inhibition works, I don’t really know.

It’s possible of course that there is a widely known and well supported explanation for this phenomenon. If so, I’ll be a little disappointed that it didn’t come up last week. But I rather doubt it does exist. One of the themes of the talks was that there was much less research on bilingualism than you’d expect, given how big a feature of the world it is. And most of the relevant data being discussed seemed to be from very recent studies. So I think until recently we didn’t know many of the facts to be explained, let alone have an explanation of them. Still, this is not at all an area I’m an expert in, and I’m sure many TAR readers will be able to point to more informed speculation than mine.

The talks at the Weinberg Symposium were videotaped, and I believe they’ll be posted to the web shortly. I’ll update this post when that happens.

Thanks again to Marshall Weinberg for sponsoring this event. Marshall sponsors many, many things at the University of Michigan (including my job!), and the intellectual environment here is much richer for it.

8 Replies to “Bilingualism”

  1. Hi Brian, I didn’t quite get the analogy with the system 1 vs. system 2 framework (full disclosure: I’m quite skeptic about dual-system accounts of cognition). In particular, there are lots of skills that we can learn at later stages, initially by relying on conscious processes, which then become fully incorporated and automatic. Driving is the best example I can think of. So I don’t see why we couldn’t learn a new language in a self-conscious way and then later, speaking the language would become largely a ‘system 1’ process.

  2. Just been rereading Terrence Deacon’s Symbolic Species, which has a prettily counterintuitive suggestion about why languages are best learned young – he argues that languages have evolved to be learnable by infants, and that because infants have limited working memory all languages have evolved only to be learnable if you can’t retain so much detail that you get confused by it.

    Which raises the pretty fantasy that there might be a way to create just the right distractions to enable us to learn a second language in the same way that we learned the first, by preventing us from focusing on it well. But I’ve not heard of anyone trying to do that.

  3. Hi Brian,

    I attended a Cog Sci talk at Rutgers roughly 15 years ago presenting evidence that (if I remember correctly) those who learned two ‘first’ languages simultaneously (both were often spoken in the home) surprisingly had deficiencies in one of the two languages, deficiencies that would not be noticed by native speakers but nonetheless were measurable. I could easily misremember the talk, so it would be interesting to hear from those in the field who know more.

  4. The phenomenon of language acquisition is an obvious specific example of the general phenomenon of synaptic pruning. If you want a ream of details you’d be best off talking to a neurobiologist who specializes in childhood development, but here’s an overly brief idea: the ability to learn and the ability to apply are often inversely correlated.

    Infants actually have a phenomenal memory, literally photographic in some testable ways. Their deficiency is not in working memory, but in focus; they lack both the experience and the commensurate neural structures to identify what they “should” and “should not” find important. This is why babies are often obsessed with things that adults find trivial. Synaptic pruning (among other things) reinforces neural pathways that are used frequently while eliminating pathways that are rarely used. This severely diminishes general learning ability and broad spectrum working memory, while substantially boosting the ability to focus on already-developed areas. Learning decreases, but ability to perform increases.

    Synaptic pruning occurs in a variety of ways at a variety of ages. Major linguistic pruning is completed at age 5, which is why humans who haven’t learned any language past that age generally can’t learn a language. (The brain is also optimized for linguistic acquisition at younger ages, which is why deaf children who don’t learn ASL until age 3 are already at a substantial cognitive deficit and will almost always be outperformed by earlier acquirers.)

    And as one would imagine based on this data, it’s less about “how many” languages you know (which isn’t neurologically well-defined anyway) but rather at what age you learn them. The success of immersion before 42 months, for example, depends really only on the age and only negligibly on whether or not a first language had already been acquired. The time-frame of linguistic pruning provides a partial explanation for this: before pruning, the new linguistic information is absorbed “more directly” (whatever that means). After pruning, the ability to learn broadly is culled, but the ability to use what one has already learned is increased, so that one is more apt to learn a second language in terms of existing known languages. It’s nearly universal for adults who learn a new language to process “bonjour means hello”, rather than to directly understand the meaning of the word.

    An interesting correlate of this is that a psychologist with an MRI can’t tell you how many languages you know (again, not neurologically well-defined), but he can tell you (very roughly) when you learned them.

    Questions such as these are very interesting, but because of the highly ad-hoc nature of the brain, it’s virtually impossible to predict the answer, or even the general behavior that motivates the question, a priori.

  5. Hey StinkyKoala,

    You’re right about claiming a neurologist could not exactly know how many languages you speak or understand. We only have one language processing area of the brain. However, through an MRI you could visually see a difference when transitioning from one language to the next. There are areas in both the temporal and parietal lobe which “light up” for bilinguals speaking their native language.

    That is interesting. Especially since the temporal lobe recognizes language or “noise” and semantics.

    Whereas the parietal lobe, for this case, would be reacting more towards the relation of the noises.

    Now, does that mean a second language (ASL) is not engaging the brain to that extent? I don’t know and I think that is a topic for discussion.

    Koala, I also liked that you mentioned synaptic pruning. That is truly important. Especially since an embryo is going through this development from the womb. Noises or language is already being recognized since before they are born. Very cool.

    There is plenty of research on language and development. However, it is still young. I studies acculturation in college for some time. And although the topic is juicy it is in need of further development.

  6. Just happen to read your interesting threads.
    Wonder any studies on ‘interpreters’‘ or real live studies on brain activities of ‘’ translators ‘’.

    eg MRI or oxygen consumption, or PETs of the interpreter’s brain while actually performing their tasks. may be there is a first language site in Temporal Parietal then spreading activities into second language site?
    or a difference in progression in hearing / receiving vs spoken /expressing /Broca areas?

  7. I don’t know who was at the conference, or how diverse were the offerings, but while I grant the legitimacy of what you’ve found interesting, it seems to me that there are some complications here you’ve neglected. My impression (and I’m not a linguist) is that many linguists have a much more liberal notion about using languages than the proverbial person on the street. There are differences between the language of a person using their “mother tongue” and a well-studied person speaking it as an L2, and the more you study them, the more you find differences. (That’s my impression.) But that need not prevent the person using the language as an L2 from using it every day, and having some sort of real success. I know that deeper questions remain, but I’ve been impressed by the point that this sort of less than perfect (from one point of view) communication actually characterizes an enormous number of speech interchanges every day. (In the real world, outside of the fictitious world of monolingual English speakers of a —how shall I say it—-conservative or even intolerant stripe…)
    And I would have thought that the sorts of philosophical issues this raise are highlighted by the phenomenon of so-called (forgive me) conceptual transfer from L2 to L1. In other words, there are linguists who study bilingualism and seem to be telling us that when you learn a second language it can influence the way you think even in your first language. Yes, I know this is troubling or controversial or likely to be described as “unclear” by a philosopher. And, I don’t know what the truth is. But what linguists like Wierzbicka or Pavlenko (and others) are saying here about these matters seem to me of philosophical significance. I’ve never gotten to the bottom of them. (I am by training a philosopher, and I know I’ve not worked out the details here.) Of course, it means coming to grips with the version of linguistic relativity that they hold. (Again, that is a place-marker for something I’ve not done.) Well, as I say, I don’t know exactly which papers you heard, but this is a different aspect of the study of bilingualism which, I think, is also of philosophical significance.

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