Typologists have long observed that there are certain distributional patterns that are not evenly distributed among the world's languages. This discussion note revisits a recent experimental investigation of one such intriguing case, so-called "universal 18", by Culbertson, Smolensky, and Legendre (2012). The authors find that adult learners are…

Examined the ability of bilingual college students from Catalonia, Spain to learn a new vowel contrast as indicated by classifying the vowel, discriminating two vowels, and judging its "category-goodness." Found a lack of behavioral plasticity and that early, extensive exposure to a second language was sufficient to attain the…