Olga Khazan reflects on her struggle to recall her first language 25 years after emigrating:
I haven’t spoken Russian with any regularity since I was in my early teens, when, tired of middle-school ostracism, I decided to become as Americanized as possible. Many psychologists think that we forget languages, and other things, because of “disuse” – the memories that we don’t try to recall very frequently become more deeply buried over time. Which explains why, even though you once aced your French midterm, you can no longer remember how to declare that you would like to go parasailing with Jean-Claude this weekend.
Other studies have shown that forgetting a native language might be an adaptive strategy that helps us learn a second one. In a 2007 study, “native English speakers who had completed at least one year of college-level Spanish were asked to repeatedly name objects in Spanish. The more the students were asked to repeat the Spanish words, the more difficulty they had generating the corresponding English labels for the objects.” That is to say, the better I became at English, the more my brain suppressed the Russian inside me.