point of interest in the martha's vineyard study, conducted by william labov in 1961, were the linguistic variables (ay) and (aw) in the speech of the islanders. the findings showed that the highest rate of centralization could be seen in the group of middle-age islanders from 31 to 45. next highest rates were to be seen within the group of 46 to 60 years old. the age-stratified variation of the analyzed variables can be seen as an indicator of language change in progress, showing that the centralization of diphthongs on the island is about to decline in younger age groups. on the other hand, labov discovered that young inhabitants, who left the island for work or study, showed an increase of centralizing diphthongs after they returned, which was explained by social factors. in fact, the study can rather be seen as a further point of intersection, where the apparent-time hypothesis comes across with the controversy of the hypothesis of age-graded variation, in which "individuals change their linguistic behavior throughout their lifetimes, but the community as a whole does not change.".