The Myth of Missed Opportunities
A popular misconception regarding second-language learning is that there is a window, or critical period, for learning a second language that shuts down around the onset of puberty. In his article, “Is There a ‘Child Advantage’ in Learning Foreign Languages?” Brad Marshall points out the harm this misconception can cause. Adults may become doubtful of their ability to learn a new language. Their teachers may become skeptical too, tending to “plod through their classes feeling there is little hope of success.” When it comes to learning a foreign language, many believe that the adult brain is in “a state of shutdown” relative to the child’s “neurological state of readiness.”

Early Foreign Language Instruction is “Not a Magical Tool”
In The Age Factor in Second Language Acquisition, David Singleton concedes that in second-language instruction, “younger = better in the long run.” But this is a general rule with plenty of exceptions. The exceptions include the 5 percent of adult bilinguals who master a second language even though they begin learning it when they are well into adulthood, long after any critical period has presumably come to a close.

Both research and the informal observations of those who are in daily contact with second-language learners suggest that an early start in a second language is neither a strictly necessary nor a universally sufficient condition for the attainment of native-like proficiency. Given the enormous variation in people’s experience of second languages—even (or especially!) in the classroom—this ought to be a truism.

As John T. Bruer, author of The Myth of the First Three Years, states: “One of the dangers of the…emphasis on critical periods, is that it prompts us to pay too much attention to when learning occurs and too little attention to how learning might best occur.” Marshall agrees, pointing out that learning a foreign language in elementary school—what most researchers generally agree is the ideal time—is not a “magical tool for creating perfect second-language speakers.” Timing, in other words, is not everything.

Many assume that critical learning periods apply not only to second-language learning, but to other school subjects, like math and reading. Such beliefs, writes Bruer, have “raised needless concerns among educators.” For instance, once a critical period is over, is “lost academic ground” irrecoverable? Such concerns arise from a simplistic and over-generalized application of critical periods to learning. The extreme view that children must learn a foreign language “early or not at all” grows out of popular images of critical periods as closing abruptly, like windows slamming shut.

Foreign-Language Learning and Critical Periods
The question of whether or not there is a critical period for learning a foreign language is not easily answered. But there is certainly no specific age at which the window of opportunity closes completely. As with the visual system, the language system consists of several features, and is not, as Singleton writes, a “monolith.” Certain features of the language system may be more related to distinct critical periods than others. According to Ellen Bialystok and Kenji Hakuta, authors of In Other Words, “The controversy over the optimal age for learning a second language really hinges on the acquisition of a subset of possible linguistic features and functions.”

The Grammar-Learning Window Never Completely Closes
Although acquiring the grammar of one’s first language does seem to be subject to a critical period which ends around puberty, the issue of whether or not there is also a critical period for second-language grammar acquisition is more complex. In The Myth of the First Three Years, Bruer does not state that there is a critical period for second-language grammar learning; instead, he claims that there “may be some maturational constraints on second-language grammar learning.”

Bialystok and Hakuta complicate the response to whether or not there is an optimal age for second-language grammar acquisition even further. They point out that learning some linguistic features, like tense, seems to be affected by age; yet other linguistic structures, like word order, “are resistant to any effect of the learner’s age.” In their book In Other Words, Bialystok and Hakuta state that syntax “remains accessible throughout life, even though the circumstances of our lives may muddy that access.” Overall, “the amazing human ability to learn grammar,” they argue, “remains with us as long as we remain human.”

Phonological Acquisition Is Age-Sensitive
Unlike grammar learning, second-language phonological acquisition is subject to a sensitive period. The decline in “unaccented learning” of a foreign language is progressive, however, and not characterized by a predictably abrupt change. According to a study by James Flege, similar and not entirely novel sounds are the ones that are affected by age. In other words, new sounds are easier to pronounce with native-like accuracy than sounds that are similar but not identical to those found in one’s first language.

According to Bruer, “we know almost nothing about the stages within the critical period for phonological learning….” We do know, Bruer continues, that “the system remains plastic and able to tune itself to a second phonology…until early in the second decade of life.”

Vocabulary Learning Has No Critical Period
Of vocabulary acquisition in one’s first language, Singleton writes, “there is no point at which vocabulary acquisition can be predicted to cease.” There is also, Singleton suggests, no critical period for learning vocabulary in a second language.

According to the results of a study by Helen Neville using brain recordings, semantic information seems to be processed in the same way by both speakers of English as a second language and native English speakers throughout life. In The Myth of the First Three Years, Bruer relates this consistency in how we acquire vocabulary throughout life to brain maturation: “how we process vocabulary does not change with brain maturation, as one would expect it would if it were a form of time-limited, experience-expectant learning. It seems instead that the neural circuitry we need to process semantic information and learn vocabulary comes on-line early in development and does not change as we mature.”

Conclusion: “Younger = Better in the Long Run”
It may be that the image of a window slamming shut as an analogy for the effect of age on one’s ability to acquire a foreign language should be replaced by Bruer’s analogy of a reservoir that “gradually evaporates.” This analogy suggests a progressive rather than abrupt decline in ability over time. Regarding critical periods in second-language acquisition, Bialystok and Hakuta suggest that the difference between child and adult learners is more quantitative (or a matter of degree) than qualitative: “Overall…the evidence of a critical period for acquiring a second language is, at best, confusing.” Although the evidence, argue Bialystok and Hakuta, indicates that the learning process is the same for both adults and children, and that second-language learning is not necessarily subject to biological critical periods, they do state that “on average, there is a continuous decline in ability with age.”

Older beginners often show an initial advantage over younger beginners in learning a new language; however, over time the younger beginners usually overtake the older beginners. There seems then to be, according to Bialystok and Hakuta, a “tortoise-and-the-hare effect”; or as Singleton has put it, “younger = better in the long run.” For this reason, we should by no means discount the importance of learning a second language early. As Bruer states, “The brain and early childhood literature is correct to emphasize that second-language learning is increasingly important and that often American schools provide too little language instruction too late.”

What should be questioned or re-evaluated are the underlying assumptions that side-step the issue of how best to teach foreign languages. The “age at which one first encounters a second language,” explains Singleton, “is only one of the many determinants of the ultimate level of proficiency attained in that language.” We must not neglect other considerations, including what neuroscience is now telling us about how second languages might best be taught and learned.

References
Bialystok, Ellen, and Hakuta, Kenji. In Other Words. BasicBooks, A Division of HarperCollins Publishers, Inc., 1994.

Bruer, John T. The Myth of the First Three Years. The Free Press, A Division of Simon and Schuster Inc., 1999.

Marshall, Brad. April 16, 2000. Is there a ‘child advantage’ in learning foreign languages? Education Week. Vol. 19, number 22, pages 39, 41.

Singleton, David, and Lengyel, Zsolt. The Age Factor in Second Language Acquisition. Multilingual Matters Ltd., 1995.