An interesting finding from a recent survey: People who felt the least supported when they went vegan were more likely to stay vegan than people who felt more supported. Take a look at "Do vegans thrive in adversity?":
"In 2011 pledgers were asked at the end of the pledge about how difficult various challenges had been including “other’s attitudes” rated from 1 (very easy) to 5 (very difficult). Those who found other’s attitudes more difficult were more likely to stay vegan. Out of 49 pledgers, 13 gave a rating of 4 or 5 on the difficulty of other’s attitudes and all but one of these (92%) chose to stay vegan.""Why might those who found friends and family least supportive be the most likely to stay vegan? One obvious reason might be a third variable. Those who were most passionate about being vegan were most likely to stay vegan and also to have disagrements with others. Another reason might be that those who had trouble with lack of support or others’ attitudes became more committed to being vegan to better integrate with a new social community."Of course, the sample size is small. And there's the issue of self-reporting. But this is interesting nonetheless.
Link to survey discussion here: http://theveganoption.org/2011/12/04/vegan-pledge-statistics-adversity/