The Debunking Handbook Part 5: Filling the Gap With an Alternative Explanation


The Debunking Handbook is a guide to debunking myths, by John Cook and Stephan Lewandowsky.

This is part five of a five-part series originally published at Skeptical Science.

Assuming you successfully negotiate the various backfire effects, what is the most effective way to debunk a myth? The challenge is that once misinformation gets into a person’s mind, it’s very difficult to remove. This is the case even when people remember and accept a correction.

This was demonstrated in an experiment in which people read a fictitious account of a warehouse fire.1,2,3 Mention was made of paint and gas cans along with explosions. Later in the story, it was clarified that paint and cans were not present at the fire. Even when people remembered and accepted this correction, they still cited the paint or cans when asked questions about the fire. When asked, “Why do you think there was so much smoke?”, people routinely invoked the oil paint despite having just acknowledged it as not being present.

When people hear misinformation, they build a mental model, with the myth providing an explanation. When the myth is debunked, a gap is left in their mental model. To deal with this dilemma, people prefer an incorrect model over an incomplete model. In the absence of a better explanation, they opt for the wrong explanation.4

In the warehouse fire experiment, when an alternative explanation involving lighter fluid and accelerant was provided, people were less likely to cite the paint and gas cans when queried about the fire. The most effective way to reduce the effect of misinformation is to provide an alternative explanation for the events covered by the misinformation.

This strategy is illustrated particularly clearly in fictional murder trials. Accusing an alternative suspect greatly reduced the number of guilty verdicts from participants who acted as jurors, compared to defences that merely explained why the defendant wasn’t guilty.5

For the alternative to be accepted, it must be plausible and explain all observed features of the event.6,1 When you debunk a myth, you create a gap in the person’s mind. To be effective, your debunking must fill that gap.

One gap that may require filling is explaining why the myth is wrong. This can be achieved by exposing the rhetorical techniques used to misinform. A handy reference of techniques common to many movements that deny a scientific consensus is found in Denialism: what is it and how should scientists respond?7 The techniques include cherry picking, conspiracy theories and fake experts.

Another alternative narrative might be to explain why the misinformer promoted the myth. Arousing suspicion of the source of misinformation has been shown to further reduce the influence of misinformation.8,9

Another key element to effective rebuttal is using an explicit warning (“watch out, you might be misled”) before mentioning the myth. Experimentation with different rebuttal structures found the most effective combination included an alternative explanation and an explicit warning.4

Graphics are also an important part of the debunker’s toolbox and are significantly more effective than text in reducing misconceptions. When people read a refutation that conflicts with their beliefs, they seize on ambiguities to construct an alternative interpretation. Graphics provide more clarity and less opportunity for misinterpretation. When self-identified Republicans were surveyed about their global warming beliefs, a significantly greater number accepted global warming when shown a graph of temperature trends compared to those who were given a written description.10

Another survey found that when shown data points representing surface temperature, people correctly judged a warming trend irrespective of their views towards global warming.11 If your content can be expressed visually, always opt for a graphic in your debunking.

The Debunking Handbook, a guide to debunking misinformation, is now freely available to download. Although there is a great deal of psychological research on misinformation, there’s no summary of the literature that offers practical guidelines on the most effective ways of reducing the influence of myths. The Debunking Handbook boils the research down into a short, simple summary, intended as a guide for communicators in all areas (not just climate) who encounter misinformation.


  1. Seifert, C. M. (2002). The continued influence of misinformation in memory: What makes a correction effective? The Psychology of Learning and Motivation, 41, 265-292.
  2. Wilkes, A. L.; Leatherbarrow, M. (1988). Editing episodic memory following the identification of error, The Quarterly Journal of Experimental Psychology A: Human Experimental Psychology, 40A, 361-387.
  3. Johnson, H. M., & Seifert, C. M. (1994). Sources of the continued influence effect: When discredited information in memory affects later inferences. Journal of Experimental Psychology: Learning, Memory, and Cognition, 20 (6), 1420-1436.
  4. Ecker, U. K., Lewandowsky, S., & Tang, D. T. (2011). Explicit warnings reduce but do not eliminate the continued influence of misinformation. Memory & Cognition, 38, 1087-1100.
  5. Tenney, E. R., Cleary, H. M., & Spellman, B. A. (2009). Unpacking the doubt in “Beyond a reasonable doubt:” Plausible alternative stories increase not guilty verdicts. Basic and Applied Social Psychology, 31, 1-8.
  6. Rapp, D. N., & Kendeou, P. (2007). Revising what readers know: Updating text representations during narrative comprehension. Memory & Cognition, 35, 2019-2032.
  7. Diethelm, P., & McKee, M. (2009). Denialism: what is it and how should scientists respond? European Journal of Public Health, 19, 2-4.
  8. Lewandowsky, S., Stritzke, W. G., Oberauer, K., & Morales, M. (2005). Memory for fact, fiction and misinformation: The Iraq War 2003. Psychological Science, 16, 190-195.
  9. Lewandowsky, S., & Stritzke, W. G. K., Oberauer, K., & Morales, M. (2009). Misinformation and the ‘War on Terror’: When memory turns fiction into fact. In W. G. K. Stritzke, S. Lewandowsky, D. Denemark, J. Clare, & F. Morgan (Eds.), Terrorism and torture: An interdisciplinary perspective (pp. 179-203). Cambridge, UK: Cambridge University Press.
  10. Nyhan, B., & Reifler, J. (2011). Opening the Political Mind? The effects of self-affirmation and graphical information on factual misperceptions. In press.
  11. Lewandowsky, S. (2011). Popular consensus: Climate change set to continue. Psychological Science, 22, 460-463.

11 Responses to The Debunking Handbook Part 5: Filling the Gap With an Alternative Explanation

  1. Joan Savage says:

    Lincoln’s use of “judicial notice” is a related, but slightly different approach to debunking. He put into evidence a truth or fact so well known that it could not be refuted. His defense of Armstrong in the “almanack case” was to show that the eyewitness was lying because the witness couldn’t have seen something happening 150 feet away out in the countryside on a dark night. Lincoln used an almanack to establish that there was no moonlight at the hour in question.

    A version of “judicial notice” showed up months ago in a moment of successful debunking of climate change denial.
    Climate scientists pointed out that warm air can carry more water, and that is something on which anyone could agree.

  2. Rabid Doomsayer says:

    I think you have to start with the basics and rebuild their entire understanding. Carbon dioxide is a greenhouse gas with well defined, well measured, absorbtion bands.

  3. Merrelyn Emery says:

    Nobody likes to think they have been fooled and your run-of-the-mill denier thinks they have been pretty smart picking the ‘hoax’ perpetrated on them by climatologists and greenies. Issuing a warning at this stage of the game is likely to be met with stiff resistance as this belief is now a matter of self worth and identity.

    The promoters of denial have also exploited the lack of understanding of the basic science of GHGs amongst significant sections of our population and as Rabid says above, this must be rebuilt. You can start to sow doubt by explaining this and linking it to the increasing rate of disasters, as predicted by the science, but don’t expect any quick victories.

    Most deniers will quietly change their minds as they increasingly find themselves out of step with the majority of their significant others, ME

  4. John Tucker says:

    Castles in the sky.

    Its nearly impossible to disprove unbounded conspiracy. The diagram above in which the myth is a clean cut object is woefully misleading. These kind of beliefs are root cluster like objects with bits and pieces spread throughout the psyche of the individual holding up and supporting their entire world-view.

    Only they can de/reconstruct that.

    The problem has always been the foundation for reasonable discussion was not adequately laid. That is the requirement that valid logic and facts exclusively guide the arguments and all things be resolved to the best of your ability before building upon them. No matter how difficult it is or uncomfortable it makes you.

    Also no one all this planet has it all together from all viable perspectives, or ever has to my knowledge. Certainly some people are a bit further along in some areas and less so in others. But all of us have myth and belief present at some level as an integral part of our motivators.

    Id be careful these days not to assume educated/ignorant, teacher/student hierarchies so quickly.

    Argument is meant to reveal the truth, not to create it – Edward de Bono

  5. Leif says:

    I think more emphases needs to be on the moral and ethical implications of the “do nothing” as opposed to “do something” course of action. Let the deniers sit on the limb that they made for themselves and defend it. Climate change will speak for itself in short order. In fact it already is speaking to those with blinders not firmly in place.

  6. John Tucker says:

    More than the entire progress of installing renewables is threatened to be undone by the anti-nuclear movements demands. Demands based on conspiracy, myth and misleading “studies” even ( ). Where is the ethics in letting that continuously occur without recourse?

  7. Merrelyn Emery says:

    John, there are no ethics in that and it is as reprehensible as denying the evidence for climate change.

    Nor is it ncessary as there is more than sufficient evidence to damn nuclear. I no more wish future humanity a nuclear wasteland than I wish them a climate ravaged one, ME

  8. Mulga Mumblebrain says:

    There’s already a tremendous amount of denialist clap-trap associated with CO2 and its absorption behaviour. Remember these are talented if disreputable people that the denialist industry employs to concoct the denialist tropes that the dull mob then chant like those in the throes of religious ecstasy.

  9. Mulga Mumblebrain says:

    The denialist industry will have expended much money studying how best to mislead and how best to befuddle minds inclined to obedience to authority. We know that from the history of the tobacco harm denial industry, and from the history of advertising psychological manipulation. They love their ‘emotionally potent oversimplifications’.I find that denialists, if confronted with evidence that their beliefs are fraudulent, never, ever, say, ‘Good grief. You’ve got a point, there, old chap. I’d better re-examine my opinions’. They either simply reject further discussion, and nobody likes hectoring, or get a little shirty. Either way, I usually retreat and inquire whether it is my shout, the universal sign of a desire to call a truce in the circles that I frequent.

  10. Mulga Mumblebrain says:

    The problem with ‘conspiracy theories’ is that conspiracies, of course, do exist. It is a triumph of brainwashing in the West that the most blatant conspiracies are ignored, or DENIED, and non-existent conspiracies, like the conspiracy of Carmnist scientists to destroy capitalism through the climate change hoax, are concocted and fostered with religious zeal.

  11. Mulga Mumblebrain says:

    And, of course, organisations like TEPCO never lie or dissemble, and the WHO’s agreement with the IEA to protect atomic energy from medical scrutiny just had to remain secret for over forty years for…some reason or other that I will unquestioningly accept on the authority of such ‘honourable men’.