If so, what drives the behaviour?
This human does, it seems to true for a lot of humans. I used different drugs at different times in the 70's and 80's. I settled in on pot and a little alcohol, 3 or 4 drinks a week. I saw a nature film about a watering hole somewhere in Africa where some kind fruit tree drops its fruit which ferments on the ground. All these animals from monkeys to elephants and other species get together and get drunk on there asses. It is realy funny. Evidently we are not alone in this.
Aside from alcohol, there are no drugs that I enjoy. Even with alcohol, I don't like being intoxicated. I can't even take strong prescription painkillers. I hate that groggy disconnect that I get from them.
@JimG -- That's true for many of us, maybe even a majority, but we as a species are prone not only to get hung up on various drugs, but all sorts of other psychological states of mind as well.
Like you, I don't take even over the counter stuff unless it is absolutely (heavy stress on 'absolutely' necessary. I definitely do not like that disconnect.
I would be happy to spend my life with only with one drug, Hul Gil- the Joy plant. It would be a short but happy life. Of course, that is not an option.