This is a bit of a tangent. The issue at hand is the use of psilocybin, MDMA, and LSD, among others, by adults -- especially for healing and self-betterment. I'm not sure if you have seen the incredible research results that have been piling up. These substances are capable of relieving immense suffering and greatly improving people's lives. Of course, they are quite powerful and should be used with great care.

I have seen the incredible results of psilocybin, but these results are on adult brains.

MDMA I'm less sure about due to possible neurotoxicity, I'd need to do more research on it, but my mind isn't closed to it.

Look into the research that MAPS (and others) is doing with MDMA. Amazing results with people who are suffering from severe PTSD.

I expect it will be a powerful tool that can help people suffering from a wide variety of traumas. Side note, but we don’t understand nearly enough about trauma. Unresolved trauma is an enormous driver of human suffering. I think it may far more widespread and take many more forms than what the textbooks say.

I find trauma to be quite interesting. I believe it's real and significant, but what I'm trying to figure out is why, evolutionarily speaking. People were routinely exposed to very traumatic, violent things in our ancestral history, much more often than in present society. How would it have been adaptive to then respond to those events with trauma, which would seem to reduce our genetic fitness?

That is a really good question. I’ve wondered about that too. It may have provided some protection, as it may increase avoidance of future dangerous situations. It could also partially be a side effect of other useful emotional expressions. Or perhaps human behavior grew in complexity (more ways to hurt each other) faster than evolution could improve our emotional processing capabilities. It’s hard to say.

Relatedly, maybe humans had better ways of coping with trauma in the past, through communal bonds, more strongly shared world views, rituals, and so on.

I'd be interested to see the data on this, because I suspect occasional use (i.e. less than once every 2 weeks to one month) is not as damaging, if at all.

Occasional use is very different from the "wake and bake" style of using marijuana every hour or so. I fell into the former category, as did some friends of mine, but I knew many who were in the latter. The differences a few years on are quite profound.