Field of Science

Expensive magic is more effective

You don't need me to tell you that money can have a powerful effect on the mind. What is surprising is just how unaware people can be of its power. For example, a study published in January found that slapping a high price tag on cheap wine makes makes the pleasure centres in the brain (the medial orbitofrontal cortex) of the people who drink it shine brighter on an MRI scan.

Now another study, published in the March 5 edition of the Journal of the American Medical Association (Paper, Press Release), has shown that a similar thing happens with the placebo effect. Now, this is interesting because, to the extent that the 'miracle cures' of the god botherers have any basis in reality, they can be explained by the placebo effect.

It's already known that you can up the power of a placebo by increasing the intensity of the ritual surrounding it. Ben Goldacre explains:
We know from research that four placebo sugar pills a day are more effective than two for eradicating gastric ulcers (and that’s not subjective, you measure ulcers by putting a camera into your stomach); we know that salt water injections are a more effective treatment for pain than sugar pills, not because salt water injections are medically active, but because injections are a more dramatic intervention; we know that green sugar pills are a more effective anxiety treatment than red ones, not because of any biomechanical effect of the dyes, but because of the cultural meanings of the colours green and red. We even know that packaging can be beneficial.
In the new study, the willing subjects were given mild electric shocks, and also what they were told was a pain killer (in reality a sugar pill, of course). But there was a twist:
Half the participants were given a brochure describing the pill as a newly-approved pain-killer which cost $2.50 per dose, and half were given a brochure describing it as marked down to 10 cents, without saying why.
The result? 85% of those given the 'expensive' sugar pill got pain relief. Remarkably, so did 61% of those given the cheap pill!

So the moral for purveyors of miracle cures (shaman, Catholics and evangelicals alike): charge as much as the suckers will pay. They will thank you for it!

ResearchBlogging.org
Plassmann, H., O'Doherty, J., Shiv, B., Rangel, A. (2008). Marketing actions can modulate neural representations of experienced pleasantness. Proceedings of the National Academy of Sciences, 105(3), 1050-1054. DOI: 10.1073/pnas.0706929105

Waber, R., Shiv, B., Carmon, Z., Ariely, D. (2008). Commercial Features of Placebo and Therapeutic Efficacy. JAMA, 299, 1016-1017.

1 comment:

  1. The effectiveness of placebos raises a moral problem for humanists (and others who care about truth and human dignity). Should doctors prescribe placebos? That is, should they prescribe medicines without proven pharmacological effectiveness in order to invoke the placebo effect and without telling their patients that they have no pharmacological effectiveness?
    The advantages are clear. Placebos are always cheap, often effective and generally produce no side effects.
    The moral problem is that placebo treatment requires that doctors lie to their patients; or at least withhold important information. This runs counter to what we generally want from doctors. It also violates the doctrine of informed consent – how can my consent be informed if important information has been concealed?
    So we patients can have the advantages of placebo treatment or the dignity of being properly informed. Which should they get? Which would they want? Or is their a way to square this troublesome circle?

    ReplyDelete

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