Researchers Conducted Six Studies To Investigate How Best To Challenge Science Deniers

via James Mathurin/Flickr

By Jesse Singal

When responding to science denialism (or, for that matter, any sort of false or harmful information), such as claims that vaccines are ineffective and harmful, it can be difficult to establish the right strategy. Because of the fast-paced way in which information spreads these days, there is a risk that responding to a given inaccurate claim can give it further oxygen, leading the falsehood to reach more people who are vulnerable to being misled, and so forth. There’s also the possibility of the “backfire effect” – people who already endorse the false claims reacting to the debunking information by digging into their beliefs further (though there’s now evidence such fears were overhyped, and that the backfire effect may not be a regular occurrence overall).

To better understand when science-denialism debunking does and doesn’t work, Philipp Schmid and Cornelia Betsch, both of the University of Erfurt in Germany, ran a series of studies that involved online respondents being exposed to various sorts of science debates. The results, published in Nature Human Behavior, offer some useful insights about how to best stem the tide of science denialism.

As the authors explain, there are two primary tactics used to rebut science denialism (and to argue in general): “An advocate can aim to overwhelm the opposing position by providing support only for her own view or she can aim to refute the opposing position by attacking its plausibility and explaining why it is wrong.” This is called a topic rebuttal. The other tactic is known as a technique rebuttal: The debunker can highlight the common techniques used by science deniers and show how a given argument fits in. For example, the claim that vaccines aren’t 100 per cent safe reflects a so-called “impossible expectation”, since no medical procedure is 100 per cent safe.

This chart from the study nicely lays out the differences between topic and technique rebuttals, with some examples:

Screenshot 2019-07-10 at 11.10.24.png
via Schmid & Betsch, 2019

The researchers ran six online experiments on almost 1,200 participants dealing with vaccines and climate change, in which they gauged success based on participants’ behavioural intentions and attitudes (either getting vaccinated or taking action to fight climate change, depending on the study, and attitudes towards those activities) before and after listening to, or reading a debate with, a science denier. Participants were randomly assigned to conditions where a science advocate was or wasn’t present to respond to the misinformation, and where the advocate used topic rebuttals, technique rebuttals, or both.

This figure runs down some of the key results:

Screenshot 2019-07-10 at 11.12.00.png
via Schmid & Betsch, 2019

Most importantly, “The results show that public discussions with a science denier have a damaging effect on the audience, as revealed by negative changes in attitudes and intentions [toward vaccination/ tackling climate change].” This negative effect was still present, though it was mitigated, even when a debunking advocate was absent. The researchers’ advice based on this rather disheartening outcome was that “advocates who take part in debates should not expect too much for their efforts — but that it’s still important to at least rebut science denialists when they show up or write in public forums.

Topic and technique rebuttals had the same mitigating effect and there was no evidence that using a combination of the two provided any additive benefit. On a positive note, the researchers found no significant evidence of a backfire effect in this context.

There are some important caveats here: This is an online study that didn’t track real-world behaviour, but rather self-reported attitudes and behavioural intent. As the authors themselves note, longitudinal studies looking at actual behaviour would be useful. But society is early on in understanding, in a scientific way, how persuasion works in this sort of context, and an investigation like this provides some firm early building blocks. Perhaps most importantly, it provides solid evidence that, from the point of view of concerned science advocates, if the choice is to show up to a debate with a science denialist or stay home, showing up is likely the better course of action – the only exception being if the advocate has the power to prevent the debate from occurring at all by abstaining.

But overall, people should temper their expectations about the efficacy of this sort of debunking: the authors argue that “facing deniers in public debates can be only one building block in the concerted effort to fight misinformation. Other recent approaches try to fight misinformation by pre-emptively providing laypeople with the ability to identify false information themselves.” At the risk of slipping into cliches about teaching a man to fish, it does feel like early, robust education on critical thinking and evaluating evidence could be more effective than trying to dislodge false beliefs one by one later on in life.

Effective strategies for rebutting science denialism in public discussions

Image via James Mathurin/Flickr

Post written by Jesse Singal (@JesseSingal) for the BPS Research Digest. Jesse is a contributing writer at BPS Research Digest and New York Magazine, and he publishes his own newsletter featuring behavioral-science-talk. He is also working on a book about why shoddy behavioral-science claims sometimes go viral for Farrar, Straus and Giroux.

9 thoughts on “Researchers Conducted Six Studies To Investigate How Best To Challenge Science Deniers”

  1. What is a “science denier”? I’m always getting accused of “denying science” and even get asked why I’m using my computer if I don’t believe in science. Transpires though that by “science denier” they mean I don’t subscribe to their metaphysical presuppositions, namely some type of materialism or that scientific theories depict a literal state of affairs etc.

    //For example, the claim that vaccines aren’t 100 per cent safe reflects a so-called “impossible expectation”//

    I get sick to death of being reassured that some medication or some medical procedure is 100% safe only for it to transpire it’s screwed up my body in some way.


    1. Science has never been about certainty. Being open to changing or discarding your theory if the evidence supports it is core to the scientific method. That means, inherently, that science can never really be purporting certainties, but models and strong probabilities. Denying science based on the idea that they’re purporting certainties that don’t turn out to be certainties seems to be a case of misrepresenting what scientists are saying. They probably mean they are extremely likely to be safe, in the case of medical procedures, and that shouldn’t be taken as 100% certainty. If they’re telling you it is 100% certain, then that’s very likely their fault for misleading you, not science as a practice.


      1. I am aware of the nature of science, how certain it is etc. Indeed somewhat more than scientists are. Nor am I even saying that scientists claim their theories are certain.

        Your post is not saying anything relevant to what I originally said.


    2. Simple question, hopefully. Do you deny conclusions that were arrived at though rigorous application of the scientific method? Do you instead subscribe to conclusions that were arrived at through perhaps less rigor? I think this is a reasonably adequate working definition of a “science denier”.


      1. I have no idea. What conclusions are you talking about? I’m interested in arriving at provisional conclusions that are the most likely to be correct. This may or may not be what scientists believe.

        PS No such thing as the scientific method.


  2. This is something that many people encounter sooner or later, whilst trying to ‘win’ an argument with a non-rational person. My experience has taught me that you need both agreed definitions and rules of logic, to establish who is right. If you attempt to argue with a Christian, Muslim or Jew, you soon realise that they have deductively formed an opinion and then gathered evidence to support their position. However religionists often have a significantly inferior standard of evidence than scientists. It is simple to disprove God from within a deterministic framework. First every thing that exists at a macro level, is invariably caused by antecedent factors and is purely reducible to prior cause. If God did exist, then he or she would just be another automaton, who’s behavioural outputs imply a viewer or agency. Thus for determinists, God is a possibility, but one which would be yet another being with the illusion of consciousness.


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