The Subset- Superset Asymmetryhypothesis and Its Applicabilityto the Periphery of Language

Wexler and manzini (1987) proposed an asymmetry hypothesis called the subset- superset directionality hypothesis which is applicable to the core of language. this study is an attempt to figure out whether the hypothesis is applicable to the periphery of language, and also to make a comparison between generativists view and that of contrasitivists in this regard. to accomplish this goal, 90 adult, female, persian speaking learners of english as a foreign language were chosen from among the students at the iran language institute. based on their performance on oxford placement test, they were divided into three groups at different levels of l2 proficiency, namely, low, mid, and high. the data were collected through conducting a vocabulary test (a 90-item translation-task) which contained 40 pairs of vocabulary; one for english as the superset and the other for persian as the superset. to investigate the data, two one-way anovas and three related t- tests were computed. the data analysis indicated that language learning is easier when foreign language (in this case, english) is superset and the first language (in this case, persian) is subset; and this is exactly what the subset- superset directionality hypothesis claims. so, according to the results, language learning patterns can be applicable to the periphery of language as well as the core. moreover, brown’s (1987) hierarchy of difficulty is rejected in this regard, but not that of krzeszowski (1990).