In the early 1960s, the linguist William Labov travelled to Martha’s Vineyard, a small island three miles off the coast of New England, to interview some of its inhabitants. There he found a community made up of three distinct groups: the native Wampanoag people and two groups of European descent: the descendants of English settlers who had first arrived in the seventeenth century, and a Portuguese community who had inhabited the island for four generations. Labov wanted to understand how the everyday use of English (the common language) varied within the community. He decided to examine the slight nuances in the way the same word, say bath, is pronounced by different groups (for example, in the south of England bath is pronounced with a long vowel, bahth, but in the north it is pronounced with a short vowel, bath). This is known as the study of linguistic variation, the active or unconscious choices made by individuals in the words they use to express themselves, and how they choose to pronounce these words. To systematically study linguistic variation on the island, Labov set about identifying a set of linguistic variables that he could unobtrusively measure. A variable here was a sound in island speech that he knew (or guessed) would vary amongst its speakers. He settled on a type of vowel called a diphthong. Most vowels, including the bath vowel, are monophthongs, meaning that the tongue stays in the same position during their articulation. However, some vowels are produced with tongue movement; these vowels are known as diphthongs. In the International Phonetic Alphabet (IPA), the system used by linguists to record pronunciations, monophthongs are represented with one symbol and diphthongs with two, the first showing the approximate starting position of the tongue and the second its finishing position, for example /baθ/ ‘ bath’ versus /hɑus/ ‘house’. For his study, Labov selected the diphthongs /ɑi/ and /ɑu/, because Vineyarders centralised these sounds to varying degrees, meaning that the initial /ɑ/ sound was produced with the tongue in a more central position in the mouth.Prior to WW2 Martha’s Vineyard was made up of isolated fishing and farming communities, but by the mid-twentieth century these industries were no longer commercially viable due to the dwindling local fish population and the increased expense of ferrying farm produce over to the mainland. Simultaneously, the island had become a popular summer holiday destination for tens of thousands of wealthy New Englanders, known by the locals as ‘summer people’. Many bought properties there and this gentrification came to be reflected in the ‘No Trespassing’ signs that had sprung up. One local informed Labov ‘You can cross the island from one end to the other without stepping on anything but [these] signs’.1 Labov found that the most conspicuous centralisation was exhibited by middle-aged fishermen, those whose traditional livelihoods were being replaced by the ‘summer people’. This group also clearly resented the tourists’ presence; Donald Poole, a lobsterman, told him, ‘You people who come down here to Martha’s Vineyard don’t understand the background of the old families of the island’.2 Later whilst dining with the family, Labov noticed that Poole’s middle-aged son, also a fisherman, spoke with the highest degree of centralisation that he had encountered so far. His mother explained that his accent had apparently developed after his return to the island having tried out and turned down city life: ‘[H]e. didn't always speak that way… it's only since he came back from college. I guess he wanted to be more like the men on the docks’.3 Moving on to the Portuguese community, Labov found that the older generation, who had not fully integrated with island society, tended to use little centralisation. In contrast, the younger generations, who were generally more involved in the local community, showed an increased amount of centralisation compared to their elders.Elsewhere, Labov found further links between islander loyalty and centralisation. Of the high school students of English descent, those students who expressed a desire to leave the island in the future tended to use mainland pronunciations. On the other hand, their peers who planned to stay on the island did use centralisation — presumably in a show of loyalty to the ‘islander speech’ of the fishermen, whom the community ‘held in high esteem’4 for maintaining their precarious traditional livelihood.Labov’s findings provided a novel insight into the dynamics of linguistic change. The Martha’s Vineyard study showed that language use was related to social variables such as loyalty — a factor hitherto ignored by linguists. Labov’s work was instrumental in establishing a new field of study known as Variationist Sociolinguistics — the study of linguistic patterns of change within sociological contexts (of which Martha Vineyard was a microcosm), helping to further our knowledge of the relation between language and society. Half a century after Labov’s original study, Martha’s Vineyard remains a popular tourist destination. Subsequent sociolinguistic studies have found that there is still a correlation between vowel pronunciation and a sense of belonging to the island, and that residents still have concerns about large-scale tourism and its impact on their livelihoods.5 Thus, social factors driving the linguistic change appear to be very much alive.On the whole, then, language is an important factor in group identification, solidarity and the signalling of differences. When a group is marginalised or under threat, as was the case in Martha’s Vineyard, overt signals of linguistic difference can become an important means of preserving identity and independence.6