Psychologists usually expect ambivalence to be a driver of political apathy. But a new study appears to show a link between ambivalence in our views and the likelihood that we’ll support extremist actions. Madeleine Finlay speaks to the study’s co-author Richard Petty, professor of psychology at Ohio State University, to find out what pushes people to take extreme actions, how politics could be driving this behaviour and how it could be combated. Help support our independent journalism at theguardian.com/sciencepod