Hansen, Colver et al. (2012) was an impressively large study of lexical attrition among missionaries who had learned second languages as adults. The study also contributed strongly to our knowledge of lexical attrition by comparing results from languages that take less time to learn for native English speakers (Spanish, Portuguese and German) and from languages that take more time (Korean, Mandarin and Japanese). This study was important because the circumstances of learning most of the languages were quite similar but the incubation periods lasted up to 50 years, making this one of only two long-term lexical attrition studies. The other long-term study, Bahrick (1984a, b), was not nearly as precise as Hansen, Colver et al. (2012) in establishing the vocabulary that the attriters would certainly have known.
However, Hansen, Colver et al. (2012) perhaps raises more questions about lexical attrition than it answers. The study found that there was much greater attrition in Japanese, Korean and Mandarin than in the languages that are generally easier for English speakers to learn. This factor of language distance is an important consideration that has not hitherto been considered adequately in lexical attrition studies. This study also showed that what Larson-Hall (2019) termed catastrophic loss of L2 lexicon, defined as being unable to produce more than 50% of a list of words which are known to have been learned by a participant before their incubation period, could happen as early as three or four years after the onset of an incubation period. Such drastic and quick change has not been previously noted in any studies of lexical attrition.
The present study thus seeks to add to our knowledge of one language which was found to be one of the most difficult in the Hansen, Colver et al. (2012) study--Japanese. I tested 50 former English L1 Japanese L2 missionaries on their productive recall of 100 words. A semantic fluency and two 1-minute speaking tasks were added to ascertain whether those without regular exposure to Japanese retained an intact lexical system. Participants with incubation periods ranging from 1-50 years were tested. Preliminary results show that missionaries scoring less than 70% on productive tests lost their ability to do more than produce strings of formulaic sequences in spoken Japanese.
Bahrick, Harry P. (1984a). Fifty years of second language attrition: Implications for programmatic research. The Modern Language Journal, 68: 105–118.
Bahrick, Harry P. (1984b). Semantic memory content in permastore: 50 years of memory for Spanish learned in school. Journal of Experimental Psychology: General, 113: 1–29.
Hansen, L., Colver, A., Chong, W., Pereira, H., Robinson, J., Sawada, A., & Miller, R. M. (2012). The lost word. Second Language Acquisition Abroad: The LDS Missionary Experience, 45, 111.
Larson-Hall, J. (2019). L2 Lexical Attrition. In The Oxford Handbook of Language Attrition.
