Evolution and income

Chris Blattman posted this graph showing per capita income against "belief" in evolution a couple of weeks ago. I have a different interpretation of it than he does, one that is cued by the very term "belief in evolution". This graph does not show, I would argue, anything about income and scientific literacy. Most of those who report that they believe in evolution rather than creationism know no more about the matter (which is to say they know nothing about the matter) than most of those who report believing in creationism rather than evolution. They are just signaling either red or blue team membership or else their relative willingness to take things on faith from people dressed in lab jackets rather than people dressed in robes. I am not sure it is a bad thing to have some heterogeneity on that score, as the lab jacket types do not always get it right and, more broadly, will likely do better if they have some competition.