Mechanism, Salience, and Belief Change

New APPS readers probably remember Helen De Cruz's excellent post on the polarized debate surrounding evolutionary science (which was picked up by NPR), as well as Roberta Millstein's follow-up post on the perhaps equally polarized debate concerning climate change. Both posts cite the work of Dan Kahan, who has a distinct take on these issues:

"I study risk perception and science communication. I’m going to tell you what I regard as the single most consequential insight you can learn from empirical research in these fields if your goal is to promote constructive public engagement with climate science in American society. It's this: What people “believe” about global warming doesn’t reflect what they know; it expresses who they are."

I just attended a talk by Michael Ranney, who opposes Kahan's position. In Ranney's view, communicating the mechanism of global climate change is enough to change the minds of people on both sides of the political spectrum. (Check out the videos!) Ranney shows, surprisingly, that just about no one understands the mechanism of climate change (Study 1). Further, he shows that revealing that mechanism changes participants' minds about climate change (Study 2). 

Why might this be?

Ranney claims that mechanistic explanations are more convincing than other explanations, citing the work of Frank Keil. This alone is an interesting possibility. But his explanatory statements and videos (see also this page) do more than just offer mechanistic explanations. First, they provide short explanations. As Rottman and Keil put it, "We are frequently confronted with complex scientific explanations of phenomena such as global warming, diabetes, and nuclear reactors. Given the immense potential breadth and depth of such explanations, we need ways to avoid being overwhelmed by the information." A short, salient explanation makes it possible for participants to avoid being overwhelmed by details. Second, they use a rhetorical strategy as old as Socrates--put your interlocutor on their back foot. In every video but the shortest, the videos start by asking the viewer to come up with their own explanation of global climate change or global warming (see, e.g., the 2-minute version), then the voiceover proceeds to explain that almost no one understands global warming, finally providing the explanation required. One member of the audience wondered whether this rhetorical strategy would yield the changes found in this study even without the mechanistic content. So here we have three possible explanations, which may well be working together in this case: our beliefs are more easily changed when confronted with 1) short, 2) mechanistic explanations of the phenomena that 3) begin with the rhetorical strategy of showing us that we don't know something we think we already understand. I suspect that philosophers might have something to say about any one of these three possibilities. But I want to say a little more about the first explanation--that shorter, more salient explanations are more likely to change one's beliefs. 

Why do shorter, more salient explanations move us? Perhaps because we regularly confuse cognitive fluency (e.g. familiarity) for truth. I am reminded of this piece in the Boston Globe: "The persuasive power of repetition, clarity, and simplicity is something that people who set out to win others’ trust - marketers, political candidates, speechwriters, suitors, and teachers - already have an intuitive sense of if they’re good at what they do. What the fluency research is showing is just how profound the effect can be, and just how it works." This research might explain why the style of what is often called "analytic philosophy" is so compelling, for instance. And, yet, the article goes on to explain the problem with cognitive fluency--we accept its content too readily: "In other words, to get people to think carefully and to prevent them from making silly mistakes, make them work to process the question: make the font hard to read, the cadence awkward, and the wording unfamiliar." The fact that something is easier to read might make us more willing to accept it, but a deeper reading sometimes requires more superficially difficult writing. Perhaps this is a partial exoneration of the style of what is often called "continental philosophy"? At the very least, as we learn what helps us to change the minds of others, we also learn when to be cautious of being so changed. (But, again, check out those videos!)