I think I know what you are looking for, but I can't find it either. I thought it was a Scott Alexander / Slate Star Codex / Astral Ten Codex article that covered the Yanomami or similar group in South America which use a nominally toxic plant as a significant part of their diet. You have to prepare it in a specific time consuming manner, and if you don't you'll eventually accumulate enough toxins that you'll die, but the timeline for poisoning is measured in years/decades, so you have to trust the advice of your elders who have passed this wisdom down through oral traditions across the ages. Young upstarts could ignore this passed down wisdom, saying "show me the evidence", (which the elders don't have) and decide to not go through the tedious preparation, and then not die after a day, or a month, or even a year's worth of consumption, but still pay the price in the end.
I think I know what you are looking for, but I can't find it either. I thought it was a Scott Alexander / Slate Star Codex / Astral Ten Codex article that covered the Yanomami or similar group in South America which use a nominally toxic plant as a significant part of their diet. You have to prepare it in a specific time consuming manner, and if you don't you'll eventually accumulate enough toxins that you'll die, but the timeline for poisoning is measured in years/decades, so you have to trust the advice of your elders who have passed this wisdom down through oral traditions across the ages. Young upstarts could ignore this passed down wisdom, saying "show me the evidence", (which the elders don't have) and decide to not go through the tedious preparation, and then not die after a day, or a month, or even a year's worth of consumption, but still pay the price in the end.