Julie Sedivy writes: Like a household that welcomes a new child, a single mind can’t admit a new language without some impact on other languages already residing there. Languages can co-exist, but they tussle, as do siblings, over mental resources and attention. When a bilingual person tries to articulate a thought in one language, words and grammatical structures from the other language often clamor in the background, jostling for attention. The subconscious effort of suppressing this competition can slow the retrieval of words—and if the background language elbows its way to the forefront, the speaker may resort to code-switching, plunking down a word from one language into the sentence frame of another.

Meanwhile, the weaker language is more likely to become swamped; when resources are scarce, as they are during mental exhaustion, the disadvantaged language may become nearly impossible to summon. Over time, neglecting an earlier language makes it harder and harder for it to compete for access.

According to a 2004 survey conducted in the Los Angeles metropolitan area, fewer than half of people belonging to Generation 1.5 — immigrants who arrive before their teenage years — claimed to speak the language they were born into “very well.” A 2006 study of immigrant languages in Southern California forecast that even among Mexican Americans, the slowest group to assimilate within Southern California, new arrivals would live to hear only 5 out of every 100 of their great-grandchildren speak fluent Spanish.

When a childhood language decays, so does the ability to reach far back into your own private history. Language is memory’s receptacle. It has Proustian powers. Just as smells are known to trigger vivid memories of past experiences, language is so entangled with our experiences that inhabiting a specific language helps surface submerged events or interactions that are associated with it. [Continue reading…]