Based on a Facebook survey where people self-selected their education level, in which a significantly larger proportion of respondents claimed to have a PhD tha

Based on a Facebook survey where people self-selected their education level, in which a significantly larger proportion of respondents claimed to have a PhD than would be expected (compared to a random sample of the US). Still an interesting data point which could be worth following up on with a more rigorous study, but easy to see the potential for skewed results.