How to Avoid the Backfire Effect and Change Minds
Contrary to what we might think, when presented with facts that run counter to what we currently believe we have a tendency of hardening, not softening, our currently held beliefs. This tendency is called the backfire effect and was discovered by researchers investigating how memory and knowledge are updated after correcting information has been received. The backfire effect works in several ways. Firstly there is the familiarity effect, the more someone is familiar with a claim the more likely they are to accept it as true. So, just mentioning a false claim, even if the purpose is to debunk it, will have the effect of increasing its familiarity and so the likelihood of it later being remembered as true. With this in mind, it is best to just focus on the facts if possible. Secondly, there is the overkill effect, information that is easier to process is more likely to be accepted as true. If we provide too many counter-examples, we will overwhelm our audience making our argument less likely to be accepted than if we had focused on one or two key points. The final and most important of these is the worldview backfire effect, this happens when the information relates to one's self-identity or political outlook. In these cases confirmation, and disconfirmation, bias will be working at their strongest as the tendency is to reject things that do not cleanly fit with the narrative of our current belief system. We should therefore be most cautious and self-reflective when considering facts that challenge that which we hold most dearly.
So, with all this in mind are we better off abandoning rational argument altogether? Not at all, but we should use this knowledge to act in a way that will be most effective. Instead of trying to bludgeon people into submission with brute facts we should get them to think about their thinking and to consider how they have formed and structured their beliefs. A cue can be taken from the ancient Greek philosopher and social gadfly Socrates who made himself a perpetual thorn in the side of respectable Athenian society, not by pushing his own views, but by endlessly questioning the assumptions of others. It has been shown that we tend to overestimate the completeness of our own understanding. By getting people to explain how and why they think something in detail, we encourage them to look at all the complexities of the issue and make any gaps in their knowledge apparent. When this method has been tried experimentally it has been found to have the effect of softening the certainty that a view is held. Once a gap has been made in someone's mental model the time is right to introduce an alternative explanation, preferably one that explains all the observed features of the event. People tend to prefer a faulty explanation to no explanation at all.
Effective discussion is as much about social skills and awareness as it is about logic and reasoning. The philosopher Daniel Dennett suggested the following method for achieving a more productive exchange. First, restate your opponent's argument in as clear a form as possible. Then mention any points of agreement, especially non-commonly held ones. State anything new that you have learnt from the argument. Then, only after these first three steps, are you permitted to put forward a rebuttal. By showing that you have taken the time to properly understand your opponent's argument and by indicating what in it you find of value you will already be starting the discussion off on a fertile footing.
Knowing about the common mistakes that we all make enables us to think more clearly about our thinking and so have a greater hope of coming to conclusions that are closer to the truth. If we want to be critical thinkers we should self-identify with the process of critical thinking and not with particular conclusions, that way we can more easily change our opinions in the light of new evidence. We should be seeking to get our politics to fit the facts and not bending the facts to fit our politics. Our default mode of thinking is to retrospectively rationalise reasons to justify our pre-existing beliefs, and by realising this and applying it to our own thinking we are more free to follow the process of reasoning and follow the logic and evidence to wherever it may take us.
Addendum 3rd July 2017: A new study suggests that the backfire effect may only apply in rare cases. http://www.poynter.org/2016/fact-checking-doesnt-backfire-new-study-sugg...