I recently came across a study just published by a group of sociology professors testing our ability to make decisions based on facts. It takes a little explanation, but it is worth looking at. The question they asked: Why does public conflict over societal risks persist in the face of compellng and widely accessible scientific evidence? To find out, the professors asked 1,111 participants a series of questions designed to gauge their political views, and then they were asked to solve a word math problem. Half of the participants were given the following problem:
The correct answer? Patients who used the skin cream were more likely to get worse than those who didn’t. Roughly 1 in 3 patients who used the skin cream got worse, but roughly 1 in 5 of those who didn’t use the skin cream got worse. Solving the problem requires skill in “numeracy”, basically the ability to solve math problems. (For the study, the data were reversed for half of the participants and presented so that they suggested that the skin cream did work.) 59% of those in the study got the answer wrong. The more “numerate” the study participants were, the more likely they were to get the problem right. That was true whether the participants were liberal Democrats or conservative Republicans.
The other half of the participants were given a different problem: they were asked to determine the effectivenes of laws “banning private citizens from carrying concealed handguns in public.” Participants were given data about cities that had or had not passed concealed carry bans, and where crime in these cities had or had not decreased. The numbers used in this problem were exactly the same as those in the skin-rash problem. The results are shown below: