Principles of. Most interventions
You can learn everything
Optimization of a single parameter (inflation of it's effect relative to average)
Supreme skilled teachers, convinces and recruiters
The bunch Of effects
Selection who Goes to course
Seeing a course, an experiment, a teach that practically helps people to improve life!
Does it say there is something in the method etc? (assume there'd are tangible real effects)
Following reasons play central role, making it hard to infer about an interesting effect of the putative method.
1) you can learn many things. Proper training. Enouge effort etc. Can make us master very many things. It is no surprise that teaching and training work.
2) optimization of a single parameter can influence the whole disproportionally. (relative to it's effect in the regular case)
Jokes maybe a negligible part of most operations, yet some managers will find jokes to be a central cause of their success and ability to motivate. Some people (I.e. Mark twain) make humor their central way to handle life. Some people manage sleep and rest to have their tanks of energy full most of the time, thereby giving sleep a relatively stronger role than usual (maybe sleep is central for all but this is another story). others use positive thinking. Exercise, timing, etc. As well as many seminar effects taken to an. Unusuall strength by making them central optimized etc. Etc.
Yet that something can artificially under certain conditions have a huge effect does not mean it is easily, generally central. Even that it has the potential for having huge effect maybe very limited to specific people and under very strict conditions.
3) supreme teachers skills, recruiters, sale mans etc.
Much of the effect of a course etc. Is about the teachers psonalty etc. It may say nothing about the putative method etc.
In psychotherapy research shows that it is mostly about the counselor and almost nothing comes out of the method (the difference between most methods of therapy is around zero, it is the effect of the meetings and talking)
4) placebo effect. If taking pills can heal many illnesses (most clinical trials show strong placebo effects, it is our moronic culture that somehow disdains using placebo for healing. I cannot find a more pronounced stupidity)
Having a course is clearly stronger in effect psychologically than a pill.
5) the bunch of effects. Most courses u multiple effects to get the results. It is not the central idea but the combination of many tricks etc. Go figure what is making it work?
5) selection effects. The fact that someone came to a course etc. Is itself meaning a lot. Until you take to the course half of the registrants and commpare to the other registrants you know little.
Skepticism is stupid. If something works who Cares about the reason?
The whole list of logical troubles prevent easy conclusions about the source of successes. But using the tricks etc. May be a good idea.