Ever found yourself in a heated debate with a friend where facts and reasonable arguments simply don’t seem to register? It can be extremely frustrating, shouting makes it even worse. It’s even worse when this happens in an official setting where the stakes are much more important than convincing a family member or friend, like in politics and, sometimes, in journalism. Why do some people maintain their position after being offered valid arguments and facts which any reasonable person would accept? Moreover, why do some people strengthen their position, opposite what should happen, after being offered reasonable arguments against their convictions?

Researchers at Dartmouth University studied this kind of behavior and found that in some instances there’s a sort of “backfire effect”  when you show people facts that contradict their opinions. The psychologists tested this behaviour after they asked participants whether or not they agree with the contents of a dummy story, framed around the Iraqi weapons of mass destruction controversy from the time of George W. Bush.

First, the participants were asked to fill in a questionnaire designed to survey their political orientation,  as well as other aspects of their personality. Some of the questions were framed in such a way that they assessed the participant’s thoughts on his own mortality. These questions were proposed in order to see if there was any connection between fear of death and nationalism. This writing exercise was not found to have any effect on people’s responses afterwards, though.

Each participant was then given two copies of a news story, basically both had the same content only one of the stories was slightly modified in such a way that it contradicted the other. The news story featured out of context quotes of George W. Bush claiming Iraq had weapons of mass destruction at its disposal. One of the versions of the text, however, also contained  a quote from the Duelfer Report showing that there was no evidence of stockpiles of these weapons and no programs to create them.

Participants were asked whether they agree or not with these reports. People who rated themselves as liberal didn’t agree with the story indifferent whether or not they read the correcting paragraph – a sign of bias. People who rated themselves as conservative agreed with the story. When the story with the Duelfer Report quote was shown, their initial opinion wasn’t shaken – on the contrary they held to their conviction even stronger. This is the backfire effect the researchers were talking about.

Further analysis showed that there were some environmental aspects that would amplify the backfire effect. For instance, if the participant felt the contradicting fact came from a source that doesn’t share his political views, then the participant was more likely to experience this effect. Like a sort of circumspect assumption. In a lot of conditions, actually, the mere presence of the contradicting fact made participants more sure of their initial opinion, instead of making them skeptic or at least doubtful of their initial conviction. Does this mean that presenting contradicting facts in an argument is going make things even worse? Sometimes, yes.

The full study can be read here. [story via io9]