Monday, November 29, 2010

Can psychology help combat pseudoscience?

From homeopathy to dodgy nutritional supplements, support for pseudoscience and quackery thrives on people believing falsely that one thing causes another, when in fact it doesn't. Meanwhile, psychologists study belief formation, and specifically illusions of control (see earlier), whereby people wrongly believe that they're controlling something when they're not. In a new paper, three psychologists at Deusto University in Bilbao argue that the psychological literature can be mined for ways to help combat pseudoscience, and they've performed a small study to test the principle.

One of the psychological findings that Helena Matute and her colleagues focus on is that people are particularly likely to form an illusion of control when: (1) a desired outcome occurs frequently and (2) they, or someone else, perform some ineffectual action lots of times. In the context of health, this would be akin to having a condition from which recovery occurs frequently without intervention (e.g. back pain), whilst at the same time receiving a frequent, but ineffectual, treatment. This leads to the inevitable pairing of the desired outcome with the ineffectual intervention, thus giving rise to the false belief that the intervention is causing the positive outcome.

Matute's team tested this in a fictional scenario. One hundred and eight participants (recruited online) read about a fictional medicine 'Batarim' that could potentially cure the pain caused by a fictitious disease 'Lindsay Syndrome'. They were told about 100 patients, one at a time, in each case learning whether the patient had been given Batarim and whether their pain had subsided.

Crucially, half the participants heard about 80 patients who'd taken the drug and 20 who hadn't, whilst the other participants heard about 20 patients who'd taken the drug and 80 who hadn't. For both groups, the rates of recovery, at 80 per cent, were the same regardless of whether patients had taken Batarim or not - in other words, on this evidence, the drug doesn't make any difference to recovery rates.

Next, the participants were asked to rate the drug's effectiveness. All of them believed the drug had had some effect, thus showing how easily confused people are about issues of cause and effect. The key finding, however, is that those participants in the group who'd heard about just 20 patients who'd taken Batarim were far more accurate in their appraisals. Presumably this is because they'd had the opportunity to see that recovery often occurred without the drug, whereas participants in the other group were blinded by the more frequent pairing of drug with recovery (even though they too witnessed recovery occurring at just the same rate without the drug).

Matute and her colleagues said this suggests a simple way for pseudoscience claims to be challenged on TV and in news reports: '...simply showing participants the actual proportion of patients that felt better without following the target treatment helps them detect the absence of contingency for themselves. This should counteract the effect of all those miracle-products advertisements that focus their strategies on presenting confirmatory cases.'

Another finding from the psychological literature that Matute's team focused on relates to the wording used in questions about cause and effect. They predicted that people are more likely to endorse pseudoscientific beliefs when asked how effective a given treatment is, compared with when asked whether it caused the desired outcome. The latter should focus people's minds on the probabilities involved. That's exactly what was found in the current study - participants gave the fictional drug more realistic ratings when asked whether it had been 'the cause of the healings' compared with when asked how 'effective' it had been.

The main point of this study was to demonstrate, in principle, that findings in psychology can be exploited to help combat the ubiquity of pseudoscientific belief, and Matute's team feel they've done that. 'Our research proves that developing evidence-based educational programmes should be effective in helping people detect and reduce their own illusions,' they said.
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ResearchBlogging.orgMatute, H., Yarritu, I., and Vadillo, M. (2010). Illusions of causality at the heart of pseudoscience. British Journal of Psychology DOI: 10.1348/000712610X532210

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