A Mathematical Theory for Why People Hallucinate

Most people I know who either smoke tobacco or marihuana, are addicted to either and can smoke the other without getting addicted. In my case I am addicted to nicotine, and I like smoking weed but never get addicted to it. I.e. one addiction is sufficient. But for what?

Another observation is that individuals that never smoke don't feel addicted, i.e. there is no innate attraction towards a substance, only after using it for a while.

Any smoker knows that after a while you need to smoke again.

The jokke/hypothesis is as follows: fire was important for human survival, tribes with fire were at an advantage over tribes without fire. Yet smoking is not healthy. The tribe only needs a few members to keep the fire going, so instead of innate attraction to keep the fire going (which would be unhealthy to each member of the group), only people who are initiated by the current fire-man get addicted, but should get addicted lest they not neglect the fire (i.e. a biological timer reminding you to inhale from the portable pipe). This way nomadic tribes that had a propensity for addiction had access to fire and its applications, and the tribe survived better than those tribes that could not get addicted (and occasionally lost their fire, possibly executing the specific fire-man at fault, a selection pressure).

I say joke, and that I don't take it serious for multiple reasons: species that probably never benefitted from fire -like spiders- feel the effects off say nicotine.

Another hole in the theory is that tobacco was imported after the discovery of the new world. But I can immagine other plants having fulfilled similar roles.

I'm saying we may never know the real story, in that no single theory might ever accumulate enough backing evidence to be proven correct, by virtue of the processes being examined. SAH operates in a space where we may only find utility in thought experiments.

I can see one or two points of evidence emerging, that could simply blow SAH to bits and put the nail in the coffin of debate. But just as easily, I could see a fossil jump out of the ground, and upend our thinking overnight. The evolutionary tale of human prehistory is that brittle, based on what we have in front of us right now.

The only ways I see SAH being proven, are forward looking replication of results, or longshot statistical truths, found in subtle clues which are very hard to measure, all in one place. Meanwhile, literally any other theory could burst onto the scene with a stronger, more convincing and reasonable narrative, and bury SAH so deep in its own wild and extraordinary whimsy that we never think about it again. But neither has happened yet, so we can still navel gaze on this one.

But, take anything you want. Any externality, leveraging selective pressure, but leaving scant traces of ever even having happened, and you've got a good competing hypothesis with legs under it. Instead of psychoactive substances, why not body lice, for example, as a selective externality? Although less charismatic than SAH, just as reasonable of a story, but just as tough to tease out a smoking gun.

How would body lice influence circumstances favoring for genetic brain size? We might easily hypothesize an illness spread by one kind of louse, whereby the head lice versus the body lice is the deciding factor to produce the selective brain outcome in the same time span. But why the bigger brain on the other side of it? Same as with SAH, the brain size could be an incidental trait. That's the way bottlenecks, invasive species explosions and fitness arms races work in evolution. Some outcomes are non-deterministic, so we never get satisfying proof.