ABSTRACT
This chapter examines individual differences in second language (L2) proficiency among adult learners. Although previous psychometric studies have identified the learner's language aptitude as one important determinant of L2 proficiency, what that aptitude consists of has not yet been specified. Working memory (WM) for language may be one (if not the) central component of this language aptitude, and we present empirical evidence supporting this proposal. We also report a study we recently conducted to go beyond global correlations and specify how a learner's WM capacity may influence his or her ability to acquire native-like sensitivity to linguistic cues in L2 and to comprehend structurally complex sentences correctly and efficiently.
