Much of the second language (L2) research on individual differences has taken a correlational approach to quantify the relationships between learner-internal variables (e.g., aptitude, motivation) and proficiency. This book, in contrast, connects two lines of research on individual differences: extroversion versus introversion, which has been largely ignored in recent years (see Dewaele & Furnham, Reference Dewaele and Furnham1999), and L2 learner strategies, which have attracted researchers’ attention for over three decades as a construct of great theoretical and practical importance (Grenfell & Macaro, Reference Grenfell, Macaro, Cohen and Macaro2007).
These two variables form the cornerstone of this highly specialized volume, a revised report of Wakamoto’s dissertation. The study itself, descriptive in nature, is unique for its thrust into a relatively uninhabited region of theory and research as well as for its use of an exceptionally comprehensive battery of instruments to triangulate quantitative and qualitative data obtained over time at the group and individual (i.e., case study) levels. Wakamoto also displays a keen sensitivity to the importance of measurement by describing his instrumentation in detail, making insightful observations about the state of measurements of personality and L2 research on this type of assessment. In this underdeveloped area, however, the design of Wakamoto’s study necessarily relies on several yet-to-be tested or problematic assumptions about the variables in question (e.g., the categorical distinction between cognitive and communication strategies).
Although the study itself represents a solid step in the right direction toward explaining relationships between individual differences and their relationship with L2 proficiency, it is worth noting the potentially narrow relevance of this research beyond the context of Japanese college-age females majoring in English as a foreign language. Given this limitation, readers will appreciate the author’s conservatism in avoiding broad statements about the generalizability of a study based on an unambiguously restricted demographic of participants. Furthermore—and at the very least—this study and many of the instruments employed can serve as models for future investigations into the intersection of extroversion and introversion and learner strategies.
