Can our political beliefs actually make us bad at math?
A group of researchers asked this question and designed an experiment to answer it. They presented subjects with a difficult problem that turned on their ability to draw valid causal inferences from empirical data. They explain:
As expected, subjects highest in Numeracy — a measure of the ability and disposition to make use of quantitative information — did substantially better than less numerate ones when the data were presented as results from a study of a new skin-rash treatment.
But then the same data were presented as results from the study of a gun-control ban. Even the subjects with the highest Numeracy used their quantitative-reasoning capacity selectively to conform their interpretation of the data to the result most consistent with their political outlooks.
In the video below, the Numberphile breaks the study down.