>"Perhaps when you say in the first post "give people placebo", you mean "give the placebo to some subset of the individuals leaving the remainder untreated"?"

I meant just placebo. I am using predictive skill of the theory behind the explanations to distinguish between them, this is common in physics/astronomy/etc. As noted by asherer, placebo effect has been studied for a long time in the manner of seeing how two groups differ. There is nothing wrong with RCTs, but does near sole reliance on them (and their observational analogue) appear to have lead to cumulative knowledge and growth of understanding?