Do bilinguals have different concepts? The case of shape and material in Japanese L2 users of English

An experiment investigated whether Japanese speakers' categorization of objects and substances by shape or material is influenced by acquiring English. Based on Imai and Gentner (1997), subjects were presented with an item such as a cork pyramid and asked to choose between two other items that matched it for shape (plastic pyramid) or for material (piece of cork). The hypotheses were that for simple objects the number of shape-based categorizations would increase according to experience of English and that the preference for shape- and material-based categorizations of Japanese speakers of English would differ from monolingual speakers of both languages. Subjects were 18 adult Japanese users of English who had lived in English-speaking countries between six months and three years (short-stay group), and 18 who had lived in English-speaking countries for three years or more (long-stay group). Both groups achieved above criterion on an English vocabulary test. Results were: both groups preferred material responses for simple objects and substances but not for complex objects, in line with Japanese monolinguals, but the long-stay group showed more shape preference than the short-stay group and also were less different from American monolinguals. These effects of acquiring a second language on categorization have implications for conceptual representation and methodology.