'The Social Motivation of Sound Change' was the first of a string of William Labov's publications in the 1960s, challenging the received wisdom that studying language change in progress was impossible. Documenting generational differences in Martha's Vineyarders' pronunciation of /ai/ as in fight and /aw/ as in about in 1961-1962 revealed an ongoing change towards increased centralization of both diphthongs, as confirmed by data from the 1930s. Rather than eliciting isolated words, Labov recorded conversational speech, raising topics of interest to respondents. Interviewing 69 Vineyarders aged 15 - 90 yielded approximately 3500 instances of /ai/ and 1500 of /aw/, coded along a three point scale of centralization. Establishing change in progress, Labov's next task was to explain it. He began with social parameters that became familiar in later studies, partitioning the data in turn by speakers' gender (men > women); place of residence ('up-islanders' > 'down-islanders'); occupation (fishermen > others), and ethnicity ('Yankees' > others). Finally, he uncovered the dimension that subsumed all the others: orientation toward the island itself: centralization scores of speakers positively oriented to the island were twice as high as those of 'neutral' orientation, and 7 times higher than those with a negative orientation.
