if the change is big enough to impact his life, he’d notice
Well, it depends what he cares about. For example, if he mainly wants to be happy and live a life that feels good / satisfying, which is a reasonable goal, then he may be largely right. On the other hand, a lot of worthwhile goals that he might care about would demand creative intelligence to achieve. A significant drop in creative intelligence—a decrease in someone’s peak ability to create new things, new ideas—is not something that would be picked up in normal studies, is not something that someone would necessarily introspectively notice, and is not something that would necessarily be picked up in benchmarks like dual n-back. Further, creative intelligence is something that would plausibly, on priors, depend on subtle / delicate learning processes that could be disrupted by some psychoactive interventions. E.g. you try a difficult meaningful deep task, and then let your brain mull on that for a week or month, and come up with a novel solution, as is often done in e.g. higher mathematics. But if you’re taking amphetamines, you blitzkrieg some narrow task all day, disrupting the mulling process and overwriting the subtle internal search and training processes your brain had set up while you were engaging in the difficult meaningful deep task.
Edit: and maybe more to the point, development is definitely going to be affected by psychoactive things. I’d bet there have been experiments demonstrating very different neural development given psilocybin vs. not psilocybin. A priori, without good reason to think otherwise, messing with development is bad; we’re mostly well-tuned. This sort of thing could be falsified at least somewhat by looking at infant mice exposed to psilocybin or whatever substance.
Sure.
Well, it depends what he cares about. For example, if he mainly wants to be happy and live a life that feels good / satisfying, which is a reasonable goal, then he may be largely right. On the other hand, a lot of worthwhile goals that he might care about would demand creative intelligence to achieve. A significant drop in creative intelligence—a decrease in someone’s peak ability to create new things, new ideas—is not something that would be picked up in normal studies, is not something that someone would necessarily introspectively notice, and is not something that would necessarily be picked up in benchmarks like dual n-back. Further, creative intelligence is something that would plausibly, on priors, depend on subtle / delicate learning processes that could be disrupted by some psychoactive interventions. E.g. you try a difficult meaningful deep task, and then let your brain mull on that for a week or month, and come up with a novel solution, as is often done in e.g. higher mathematics. But if you’re taking amphetamines, you blitzkrieg some narrow task all day, disrupting the mulling process and overwriting the subtle internal search and training processes your brain had set up while you were engaging in the difficult meaningful deep task.
Edit: and maybe more to the point, development is definitely going to be affected by psychoactive things. I’d bet there have been experiments demonstrating very different neural development given psilocybin vs. not psilocybin. A priori, without good reason to think otherwise, messing with development is bad; we’re mostly well-tuned. This sort of thing could be falsified at least somewhat by looking at infant mice exposed to psilocybin or whatever substance.
That is a good point. He concedes it. He tried for “microdosing LSD promotes creative intelligence” but couldn’t back it up sufficiently.
It may be interesting to raise that the evidence for LSD microdosing having the claimed effects is looking less promising these days. https://www.nature.com/articles/d41586-022-02876-5 provides a good discussion and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9731343/ is the key placebo controlled LSD micro dosing trial result which came out in 2022.