Great Minds Keynote: Everything is a placebo

In every case we react to stimuli not in response to what they are, but in a constructed emotional response to what we believe they mean. This glorious failure of objectivity is usually viewed as a human failing, and (certainly in the case of pharmacological research) we seek to correct for it. But is this wrong? Can a little benign shamanism be used to solve problems which continue to stump rational engineers and economists.