| Younger and older brains clearly differ, but there is no proof that such differences have any significant effect on learning a second language. |
One rarely hears people over the age of 20 complain that they would be far more competent drivers if they had not waited until their teens to get behind the wheel. Nor do adults frequently lament that they would be much better managers if only they had begun taking business classes at age 5. Yet when it comes to starting a second language, there is a widespread belief that adults will inevitably have problems and will certainly never become fluent, while children are supposed to pick up languages with ease.
The result of this misconception has been that many adults quickly renounce even trying to learn a foreign language, or start studying enthusiastically but quickly become discouraged. Similarly, more than a few teachers of adults plod through their classes feeling there is little hope of success. Furthermore, while many American universities have limited foreign-language requirements, school districts across the country are introducing second languages earlier and earlier. A close look at research reveals, however, not only that very early foreign-language instruction may not be necessary to ensure proficiency in later years, but also that adults can and have mastered foreign languages.
Scientifically documented differences between an adult’s and a child’s brain have powerfully influenced people’s beliefs about learning a second language. Since Wilder Penfield and Lamar Roberts first introduced the idea in 1959, many researchers have claimed that a biologically determined “critical period” for second-language acquisition ends at or around puberty. With advances in technology, the focus on which particular characteristic of brain development is responsible for successful language learning has changed. Thirty years ago, the “critical period” was said to coincide with the process of brain lateralization. The theory was that once specialized areas for various tasks, such as language learning, were formed, it would be more difficult to acquire a new language. However, when lateralization was found to be largely completed within the first years of life, attention shifted to the development of neurons in the brain: The greater the number of connections among neurons, the better one’s capacity to learn. This has been followed most recently by research into how the body burns sugars, under the assumption that a greater use of glucose accompanies more efficient learning. While there do seem to be distinct patterns concerning neural connections and glucose uptake that are related to age, both of which peak during childhood, they have not been shown to coincide with proficiency in a second language.
Other attempts by neuroscientists to link foreign- language learning and brain development have focused on which part of the brain is used for certain language tasks. Studies have demonstrated that different areas are activated during language processing, depending upon the age when the language was learned. Karl Kim and others have recently shown, for example, that when reading to themselves, late learners of a foreign language tend to use two distinct parts of the brain, one for each language, while early learners use only one area for both languages. Yet, as with similar studies, there was no evidence that different locations of brain activity are at all associated with different levels of language proficiency. In other words, younger and older brains clearly differ, but there is no proof that such differences have any significant effect on learning a second language.
Another misconception is that young children are generally faster learners and that they somehow “absorb languages like sponges.” But studies in the late 1970s revealed that preschool children learned much less than older children and early adolescents after an equivalent amount of exposure to a second language. Ten years later, it was shown that listening skills of those in their late teens far surpassed the skills of children between the ages of 6 and 7. A well-known and influential study in 1989 by Jacqueline Johnson and Elissa Newport concluded that those who were exposed to English before the age of 15 could better judge English sentence grammar than those exposed later. Yet a similar study by the same researchers three years later, testing written rather than oral skills, found the cutoff age to be 17.
Soon after, a reanalysis of the same data by Ellen Bialystok and Kenji Hakuta not only showed that some types of proficiency did not deteriorate until after age 20, but also revealed that performance on certain tasks was completely unaffected by age. This implies that what has been referred to as the “child advantage” depends less on age than it does on the type of language skill being tested. For example, while younger learners generally have a better chance of acquiring a native accent when continuously exposed to a new language, older learners tend to master tasks related to translation, vocabulary acquisition, or grammar more rapidly.
Not only are these findings encouraging news for older students, but they also should give school administrators reason to pause before implementing traditional foreign-language programs in elementary schools rather than expanding programs at the secondary or university level.
The most common mistake that has led to an “anti- adult” bias may be overgeneralization. People assume that simply because many adults eventually encounter difficulties, this somehow means that all adults are incapable of mastering a second language. While it is true that the average performance of adults as a group may be below that of younger learners, there are cases of older learners who outperform younger ones. Even in studies purporting to show a “child advantage,” there are instances of some adult learners who perform as well as native speakers. These examples are often ignored, and yet it is precisely such “exceptions” that call into question any claim of biological limitations to second-language learning.
Reasons other than age must thus be found to explain the generally lower performance of adults. The environment in which one learns a foreign language, for example, clearly plays a major role. Children, especially those exposed to a second language before school age, often hear the new language long before they attempt to speak it. This “silent period,” according to some researchers, is necessary to allow the foreign sounds to “imprint” themselves in the mind of the speaker. Adults, on the other hand, are almost always forced to speak, either through necessity or as a result of the current conversational approach of many teaching methods, before they have adequately recorded the new pronunciation. Experimental teaching methods, such as those starting with several lessons devoted solely to listening, have in fact proven effective in generating better accents for adult learners of French.
An adult’s mother tongue can also influence how she or he learns a second language. For example, older students often find foreign languages that are very similar to their native language easier to acquire. Adults are generally more conscious of the relationship between two languages and can use similarities, such as those concerning vocabulary or grammatical structure, to their advantage. It is also useful for teachers to take into account their students’ native language in order to better understand particular errors and focus on areas that are known to pose the greatest problems for students of a certain mother tongue.
Recent research has also shed more light on the important role of psychological factors in foreign-language learning. Many studies have revealed a relationship between successful acquisition of a second language and an acceptance or desire to become part of the new language group. Other research has focused on more internal elements, such as the need to achieve or the fear of failure. Madeline Ehrman and Rebecca Oxford, in one of the few studies to analyze age and psychological variables, have demonstrated that a learner’s confidence in himself is more closely related to successful second-language acquisition than the learner’s age.
Foreign-language instruction in an elementary school is not a magical tool for creating perfect second-language speakers. |
An important implication of these findings concerning adult foreign-language learning is that we need not be panicked about exposing young children to other languages, on the grounds that they must learn early or not at all. While foreign-language instruction in an elementary school certainly can produce some learning, it is not a magical tool for creating perfect second-language speakers. Nor can we expect particularly rapid progress from young learners—five hours a week of foreign-language instruction in grade 9 will produce much more proficient speakers than five hours a week at grade 2 or 4. Finally, several years of studying a foreign language at the early- elementary level will probably generate no long-term knowledge at all unless excellent foreign-language instruction continues into the secondary school and university years.
This research also shows that the difficulties adults face when learning a new language are not due to some biological handicap that worsens with age. Adulthood does, however, present learners with obstacles that children rarely encounter. Language programs must therefore provide adults with a level playing field by taking into account factors such as a student’s native language, psychological concerns, and when and where the learner starts speaking the new language. Indeed, under the right conditions, learning a foreign language is a game that even adults can play.
Brad Marshall is a teaching fellow in the department of Romance languages and literatures at Harvard University in Cambridge, Mass. This essay is based on research by Mr. Marshall, Stefka Marinova-Todd, and Catherine Snow, published in TESOL Quarterly (“Three Misconceptions About Second Language Learning”).
