By some combination of changes in both the environment, and human biology, humans evolved on Earth in a way that basically makes them 100% unable to alter their minds using traditional methods:
- Alcohol has no mental effects
- No hallucinogens or other drugs work or are available
How would this deviation affect human development as a species?
The addition via dopamine is still possible (you can get addicted to video games or sex or Facebook).
But you don't have an option to imbibe/use any chemicals or products that alter your mental state in a measurable manner as one of those addictive things.
Some of the "real world" mind altering substances are still available (e.g, you can still brew beer so you can't claim that "according to latest research, beer significantly helped by making nutritious and bacteria free drink"). You just don't get drunk from that beer, at least the mental effects of getting drunk. You can still distill wine, and not have humans die out from drinking contaminated water in Middle Ages. Just no drunks.
The mind altering effect of "natural" things still exist. E.g. you have the same effects from lack of sleep as real humans do; or from malnutrition/dehydration; or from oxygen-poor air.
I'm interested in a couple of different but related angles:
Would it affect the biology and evolution in meaningful way?
Would it affect broad historical or cultural patterns in a meaningful way? I'm interested in stuff up until let's say a level of development of early or mid 20th century civilization wise.