The benefits of learning a language are numerous. Bilingualism in general has many mental benefits. The research that demonstrates these things, though, doesn’t tell you a crucial point: all languages are not created equal. Specifically, living languages are very different from dead ones.
I spent, depending on how intensively you define the word “studying”, between four and ten years studying a dead language. I started around age seven with Rosetta Stone Latin (yes, that exists), and studied intermittently through elementary and middle school before taking four years of intensive high school Latin, culminating in the AP test. With the exception of two brief classes in Spanish and Mandarin Chinese, the vast majority of my experience in learning languages has been with a dead one.
Last year was my final one taking Latin. After a little while, I detoxed myself of the apathy I’d acquired for anything resembling school, and I kind of missed it. Silly, right? Missing studying vocabulary lists? And maybe it is silly, but it happened anyway. So, intermittently in accordance with a busy schedule, I took up Japanese.
Immediately I was shocked by the differences in learning methods. First, a living language necessitates pronunciation. My proficiency with Latin was orders of magnitude greater than my current proficiency with Japanese: circa last spring, I could read and understand complicated books written in Latin. I read the Aeneid and the Gallic Wars in the original, which is immensely difficult: they’re huge, thick books with tiny type and long, complicated sentences. By contrast, I can hardly form simple sentences in Japanese.
But you can get to where I was in Latin without ever speaking a single word out loud.
Seriously! I learned nearly everything from written words on a page. I read silently, studied flashcards silently, translated silently. I only ever spoke a word of Latin aloud under two circumstances: I was in my one-hour once-a-week online class and I was reading a passage aloud to the class; or my linguistically-inclined brother had asked me the Latin word for something.
By contrast, the veritable instant that I began my study of Japanese I was talking. To an empty room as a pronunciation exercise, but still. The pronunciation actually mattered. I watched Japanese cartoons (commonly called anime) and repeated what the characters were saying under my breath. “Nan desu ka?” a character on the screen would say, and I’d mutter under my breath, “nan desu ka”. I learned so much vocabulary this way, and I learned it painlessly.
That brings me to another point. With a living language, there is media in that language. It’s possible to learn words and phrases purely from watching and reading content. With a dead language, this method of “learning by input” is impossible: there is no content to consume. There is no anime in Latin. I learned exclusively through exhaustive memorization of grammar. It was boring and uninteresting, and now, six months or so after finishing my studies, I’m hard-pressed to remember most of it.
The combination of these two factors—lack of pronunciation and lack of auditory input—made me feel less like I was actually fluent in Latin, and more like I was simply knowledgeable enough about its inner workings that I could basically deconstruct it like a puzzle. I think that, even at the height of my Latin knowledge, if I’d been teleported back to Ancient Rome and met with a native speaker, I could not hold a conversation.
In other words, I didn’t speak the language, I could only deconstruct it.
To hammer in this distinction, let me ask you a question: do you know what a pluperfect is? No? Here’s an example: “We had arrived.” I guarantee you use the pluperfect all the time, but you never knew what it was – and you never needed to. But with Latin, I was backwards. I knew the grammar and all its terms inside and out – if you asked me what the pluperfect subjunctive ending in the third conjugation was, not only would I have understood you, but I’d also have been able to supply the answer. However, I had literally never used any of those words in an actual conversation.
This is the most important difference between learning a living language and learning a dead one. If you learn a living language, you will come out of your studies with an ability that is practically useful: the ability to have conversations. You don’t come out of studying a dead language with that. You only come out of studying a dead language with the ability to deconstruct it.
What does all this mean for you? Take a closer look at the article I linked at the top. The reason bilingualism is helpful for improving mental acuity is that “both languages of a bilingual speaker are constantly active to some degree, even in strongly monolingual contexts”. Aka, the auditory and visual processing for both languages is always online. This makes the biggest difference in conversation, where the bilingual person’s brain has to continuously figure out which language it should use to process information: “this difficult selection is made in constant online linguistic processing by bilinguals is that the general-purpose executive control system is recruited into linguistic processing, a configuration not found for monolinguals.”
But wait, didn’t I just get done saying that one of the chief differences between living and dead languages is that you can learn a dead language completely without ever having a conversation?
Yes. That is exactly my point.
If you’re planning on learning a language for purposes of improving your mental abilities, I highly recommend learning a living one. Looking at the reasons behind the statement that “bilingualism improves your brain”, it seems to me that learning a dead language is much less likely to benefit you than a living one.
Plus, we shouldn’t deny the benefit of having conversations with others in their native tongues. To quote Nelson Mandela, “If you talk to a man in a language he understands, that goes to his head. If you talk to him in his language, that goes to his heart.”