In early August 2016, NCSE reported on the results of the latest of the National Surveys on Energy and Environment. Respondents were asked questions such as, “Is there solid evidence that the average temperature on earth has been getting warmer over the past four decades?” (66% said yes: not so bad) and “Is the earth getting warmer because of human activity such as burning fossil fuels, or mostly because of natural patterns in the earth’s environment?” (46% of those who said yes to the previous question chose human activity: not so good). Interestingly, though, the researchers also asked, “What is the primary factor that has caused you to believe that temperatures on earth are increasing?” and “What is the primary factor that makes you believe that temperatures on earth are not increasing?” (all quoted from the questionnaire [PDF], questions 7, 9, 10, and 20).
I was interested, and NCSE’s story failed to mention the responses to the “primary factor” questions, because, as a century of research shows, people are not especially accurate in their claims about why they believe what they believe. Who, after all, when asked why they believe what they believe about global warming, would volunteer “blind prejudice” or “it just seems that way to me” or “it scares me to think otherwise” over “careful and dispassionate scrutiny of the evidence”? Textbooks on survey research routinely warn against questions such as these. For instance, Weisberg, Krosnick, and Bowen’s An Introduction to Survey Research, Polling, and Data Analysis (third edition, 1996), observes, “The explanations that people offer may make sense and sound reasonable, but they often have nothing to do with the actual causes of behavior.”
In the literature on public acceptance of evolution, researchers have thus generally sought to identify correlations between, on the one hand, acceptance/rejection of evolution and, on the other hand, various demographic factors (educational attainment, degree of religiosity, political affiliation, etc.) and/or basic level of understanding of evolution and/or various cognitive factors (e.g., open-mindedness, deference to authority, need for certainty, etc.). But there are exceptions. A few years ago, in reply to a researcher who was considering whether to include a question like “Why do you believe what you believe about evolution?” on a survey instrument, I assembled a list of prior work with such questions. I don’t promise that it’s complete (n = 2) or up-to-date (four years later), but perhaps it will be of interest nevertheless.
First, in the Journal of Biological Education in 2000, J. R. Downie and N. J. Barron reported on a study of first-year biology and medical students at the University of Glasgow over the course of almost ten years. Respondents who rejected evolution (a small percentage, between 3.9% and 11.3%, depending on the year) were asked to say why and were allowed to pick any of the following: