INDIVIDUAL-DIFFERENCES IN L2 PROFICIENCY AS A FUNCTION OF L1 PROFICIENCY

This paper offers an illustration of the claim that some individual differences in a second language (L2) can be accounted for by individual difference in the first language (L1). Two studies are reported, which examined L2 performance as a function of L1 performance. In the first study, 65 Dutch learners of English performed reading aloud tasks in L2 (English) and L1 (Dutch). In the second study, 50 Turkish learners of Dutch performed reading comprehension tasks in L2 (Dutch) and L1 (Turkish) as well as 12 vocabulary and grammar tests. The results of the first study, obtained by means of co-variance analyses, show that most of the differences in L2 performance due to grade level (grade 9 vs 11) and academic level (higher vs lower) disappeared when performance in L1 was taken into account. The results of the second study, obtained by means of correlational techniques, provide support for the involvement of both an L2-specific (vocabulary and grammar) and a non-L2-specific component (as indicated by L1 reading performance) in L2 reading comprehension. Although the former appeared to be more involved, non-L2-specific factors did in fact contribute positively and substantially to the L2 reading performance of adult second language learners. Moreover, the data of the second study gave rise to the idea that the contribution of non-L2-specific factors may not be stable, but liable to changes in the course of the L2 acquisition process.