"(edit) An additional and interesting line of inquiry might be what it is that makes alcohol (as either a social lubricant or a depressant) or tobacco (as either a stimulant or a known form of slow motion self-destruction) appealing to so many people?"
I consider this, as another empty amber bottle rolls across the floor boards.
Three (or perhaps four) thoughts sprout forth from this proposition.
Considering those substances that make our lives marginally more bearable, without killing us outright, such as marijuana, tobacco, alcohol, and also (in context) coca leaf, laudnum, khat, etc...
So, working back through time*:
How do these substances help us cope with lives that are often unbearable, and which we are constantly told - that which we are unable to change in any meaningful way?
How were these substances used in context? Either as medicine, under the supervision of an elder or herb-woman; or as a component in a customary ceremony.
What effects caused these substances to be valued by pre-hierachic people? Beyond the euphorics and hallucenogenics; most of these substances block pain and fatigue, and quiet a troubled and anxious mind; additionally, nicotine and marijuana smoke have been shown to kill parasitic larvae in the lungs, and we might surmise that alcohol (especially in binges) might have the same effect upon intestinal parasites. All medicines, are poisons.
We are not the only creatures to pass through this world. May we observe which plants are used also by wildlife? (I recall that the pot smugglers in bc had a terrible time keeping the deer from chewing up their back-country plots.)
[I hope to flesh this out at some later time; but at the moment, i have the attention span of a plague flea. :( ]