Toward a Theory of Language Acquisition1

The claim that the adult, in contrast to the child, is deficient in his ability to learn a second language leads to the conclusion that adult second language acquisition is a process which is characteristically different, cognitively, from that of child first or second language acquisition. This paper challenges this claim. The differences which do exist are more quantitative than qualitative and can be discovered by a shift of attention from the cognitive domain to the affective domain and to the psychological variables of attitude, motivation, and permeability of ego‐boundaries. Five central issues are dealt with: 1) the notion of a “critical period” for second language acquisition, 2) psychological learning strategies in language acquisition, 3) the influence of the native language in second language acquisition, 4) the variable of cognitive maturity, and 5) affective psychological variables.