Chris,
Clearly testing whether a person's mood affects their chances of surviving cancer, is a very subtle matter. The experiment is very easy to do in a rather casual way - just ask them how they feel - and much harder to do in a meaningful way. I think the frustration that others have expressed here, is that a study which may have been somewhat naive, is quoted as if it were decisive.
Something similar applies to the question of the power of placebos. The fact that the only really acceptable kind of medical trial compares placebo vs drug, means that it is hard to test the power of a placebo on its own. However, at least part of the reason why medicine uses placebo controls is because the placebo effect is so powerful. We have discussed this before, but I am a bit dubious of your claim that researchers doing double blind tests are not trying to control for the placebo effect - just ensuring that they compare like with like.
Suppose that some shaman ceremony (say) is a really effective placebo for some condition. You are basically saying that you can't test the claim because it is impossible to do a double blind trial (I presume - how do you do a fake shaman ceremony?) I think you need to be careful not to build a wall of orthodoxy round yourself that you never challenge your own basis for rejecting evidence that you don't agree with - because you are already convinced no such evidence can possibly be valid!
David  |