Okay, so, I owe Brendan Nyhan big time on this one. In a debate last week that pulled in Kevin Drum, David Frum, Andrew Sullivan, Josh Rosenau, and Mike the Mad Biologist, we've been discussing whether vaccine denial is really a left wing phenomenon or not. One problem has been that the polling data on who actually resists vaccines is pretty scarce. However, there are at least two polling results out there in the universe of public opinion data that have not been discussed yet, so far as I can tell. Neither is perfect for getting at the question of who has fallen for the vaccine-autism scare, but both are relevant. Let's take them in sequence. In late 2009, USA Today/Gallup asked a question about Jenny McCarthy's anti-vax views:
Did Jenny McCarthy's statements (she believes her son developed autism after getting a common childhood vaccine) make you more likely to question the safety of vaccines for children, or did her statements not make you more likely to question the safety of childhood vaccines? Survey by USA Today. Methodology: Conducted by Gallup Organization, November 20 - November 22, 2009 and based on 1,017 telephone interviews. Sample: national adult. Interviews were conducted with respondents on landline telephones for respondents with a landline telephone, and cellular phones for respondents who are cell phone only. [USGALLUP.200921.Q21]
What Brendan Nyhan did for me was obtain the polling data from Roper, and then helped me break the results down by the political leanings of the respondents. One major complicating factor here is that not everyone surveyed was aware of McCarthy's claims. That makes the question less than ideal. Still, we can break the results down for liberals, conservatives, and moderates--and what we're trying to see is if there is any strong correlation between political views and those who said they were "more likely" to question vaccine safety after having heard McCarthy's (wrongheaded) views. So here are the results: Liberals (41% not aware, 38 % aware but not more likely, 21 % aware and more likely); Moderates (48 % not aware, 28 % aware but not more likely, 24 % aware and more likely); Conservatives (49 % not aware, 28 % aware but not more likely, 23 % aware and more likely). These results basically suggest that there's little or no political divide in terms of who falls for Jenny McCarthy's misinformation. Notably, liberals were somewhat more aware of her claims and yet, nevertheless, were least likely to listen to them. But not by a huge margin or anything. I recently stumbled on a second polling result that is also relevant, although hardly perfect for our purposes--also from 2009. In a Pew poll that year that sought to differentiate between the views of scientists and average Americans of a variety of issues, people were asked whether childhood vaccines ought to be required, or if instead it should be left up to parental choice. 69 % of Americans thought they should be required (vs 82 % of scientists), while 28 % would leave it to parental choice (vs 17 % of scientists). What's interesting here is that Pew also provided a political breakdown of the results, and there was simply no difference between Democrats and Republicans. 71 % of members of both parties said childhood vaccinations should be required, while 26 % of Republicans and 27 % of Democrats said parents should decide. (Independents were slightly worse: 67 % said vaccinations should be required, while 30 % favored parental choice.) Bottom line: There's no evidence here to suggest that vaccine denial (and specifically, believing that childhood vaccines cause autism) is a distinctly left wing or liberal phenomenon. However, I will reiterate that we don't really have good surveys at this point that are clearly designed to get at this question.