Narz
keeping it real
The placebo effect isn't very well known or understand even by most of the modern population. Of course it is understand by the educated. Just as it is understood by the medicine men & healers in tribes. They know what they do is a mix of effective treatment & showmanship (pretending to remove spirits, pretending to pull feathers out of a person's wound, etc.). One might even go so far as to say the "primitive" medicinal experts are more keenly aware of the placebo effect whereas your average modern doctor probably forgets it more often than not, carelessly giving diagnoses without thinking carefully about how his presentation of the diagnosis will affect the patient (often invoking the nocebo effect with statements like "well, you probably have six-months to life", etc.).Placebo effects and drug interactions are important things to know in medicine. Common sense is seldom good enough.
Nonetheless, if you just randomly choose compounds to test you'll find a successful one like once in a hundred years. As I've said knowing what to test is the more important thing.There are a lot of considerations for a clinical trial. A representative sample, ethical concerns...one could write multiple dissertations on the subject.
I've not comparing the medical knowledge of tribal people to the vast body of knowledge we have today but I'm saying you're wrong in saying aboriginal knowledge of medicinal plants & whatnot is worthless.