Maybe in the US where the whole AA thing is popular and widespread. I'd be surprised if that's a factor at all elsewhere. Where I'm from I've never met anyone who would label themselves as 'former alcoholics'.
I'm more inclined to think intelligence often times comes with a good dose of social anxiety and alcohol helps with managing it.
You might have zero contacts with lower working class then. I live very far from the US in a very different society and know many former alcoholics who abstain entirely, or at least try to. Because it's hard enough for an alcoholic to avoid drinking, it's even harder to have just one drink and not slide into a full-blown, months-long binge.
Back then I knew the problem was the *quality* of the alcohol/drinks.
Now, some years later. "My homie Jamal's" liquor costs 5-10 times that much and he puts effort into the mixtures, trying recipes, playing around with accent ingredients and modifiers and stuff. If we drink--we still drink quite a bit. But there's no month long binges no more and the immediate negative side effects on cognition are *GONE*.
Most AA alumni don't call themselves former alcoholics. They see themselves as addicts who are glad they didn't have a drink yesterday and are doing their best to extend that streak through today.
I'm more inclined to think intelligence often times comes with a good dose of social anxiety and alcohol helps with managing it.