Second Language Acquisition and Second Language Learning

This degree of lateralization increases until about age 5, by which time most aspects of language processing are lateralized to the left hemisphere at the adult level. This accounts for the brain damage and hemispherectomy data, which show some right hemisphere contribution to the language function before age 5.

Certain aspects of language are not entirely lateralized to the left hemisphere until later, perhaps by puberty. These aspects of linguistic competence may be those that are necessary for the perception of longer and more complex stimuli. This accounts for the exceptional dichotic listening studies.¹

Whether or not this particular schema is the correct one, one clear conclusion that can be drawn from this literature is that there is little doubt that children show left hemisphere dominance for much of the language function well before puberty. There is also no necessary relationship between cerebral dominance and second language acquisition ability. As mentioned above, alternative explanations have been proposed for child-adult differences in second language attainment, explanations that are probably unrelated to cerebral dominance. As an example we briefly sketch one possibility.

In Chapter 2 it was hypothesized that certain cognitive and affective changes taking place around puberty, possibly connected to the onset of the stage of formal operations (Inhelder and Piaget, 1958), an event which generally occurs at around age 12, may have the effect of boosting language learning potential, while limiting or weakening the language acquisition potential. This change may be responsible for observed child-adult differences in language acquisition.

At formal operations, the adolescent becomes an abstract thinker, and is able to "reflect on the rules he possesses and on his thoughts" (Developmental Psychology Today, 1971, p. 336). He can, for the first time, "take his mental constructions as objects and reason about them", and can "deal with problems in which many factors operate at the same time" (Elkind, 1970, p. 66).

The meta-awareness and ability to theorize brought about by formal operations allows the learner (or compels him) to create an abstract theory (or grammar) of the language he is approaching. Formal operations may thus allow the "conscious grammar", or