The Expectant Brain and the Placebo Magic; Does it have a Survival Value?

“The placebo effect is the reduction of a symptom or a change in a physiological parameter when an assumingly inert treatment (the placebo) is administered along with a complex set of psychological stimuli that tell the patient that a benefit may occur”.1 It is perhaps a century since the ‘placebo’ response has been clinically and scientifically investigated and established as a fact, although its magical powers have been used for millennia by ‘witch doctors’, ‘medicine men’ and ‘shamans’ in a ritualistic manner to heal the sick by expelling the causative evil spirits from the afflicted. The aim of this article is to delve into the evolutionary advantage and benefits of such a mechanism for the developing human societies and its persistence to the present day despite modern understanding of disease causation and the logic of evidence-based medicine.