By David Yamaguchi
For The North American Post
It is hard to circulate in the Greater Seattle Japanese community, where one regularly encounters strongly bilingual Shin-Issei and Shin-Nisei and largely monolingual Japanese American Sansei and Yonsei, without regularly thinking about who acquires a second language, who doesn’t, and why. The question is timely because we have an opportunity to influence which Seattle-area youth will be able to work effectively in Japan across the coming decades and fill gaps in its declining labor force.
As a Sansei who stands between the two groups linguistically, today I wanted to share the graphic shown here. New to me, it is the most remarkable picture of the second-language learning process I have seen in my entire life.
The descending lines summarize the main findings of a grammar quiz posted on the internet, to which over 669,000 responded. The upper curve shows how the second-language ability of those who immigrate to a new country varies by age of immigration.
The lower curve describes how the ability varies in non-immersion contexts, for example, through foreign-language study in school. The two curves show “that learners must start by 10-12 years of age to reach native-level proficiency. Those who begin later literally run out of time before the sharp drop in learning rate at around 17-18 years of age.” Notably, the authors place the “beginning of the end” of second-language acquisition at 17.4 years.
In summary, the key points for optimal study are to start learning the second language by age 10 and to get as far as you can by age 17. Beyond this point, you can study all you want, but you’re facing diminishing returns. Your brain is no longer flexible enough to easily acquire the second language.
A related point is that if two years of college Japanese study are in your plans, then it would be more effective to place them earlier in your course of study. This amount of exposure meets the level of study recommended by the U.S. Department of State for its foreign service workers.