If you don’t trigger any effects

OK and what about for the people who one drink does trigger an effect?

a single drink for most adults

Again, what about for the people who it does? You’re being quite absolute here. What I’m saying is you cannot use amount alone to determine whether or not it’s problematic. You said it yourself, it’s a factor. You originally used it as a determinant.

So no, that is not in fact how addiction works. I’ve spent the last 10 years studying psychology and I’m a PhD student in the field now.

That’s not how addiction works. Firstly, addiction is not a defined term in the medical or psychological fields so the conversation is kind of pointless. Secondly, amount has nothing to do with it. Lots of people have a “nightcap to help them sleep” every night. That is dependence and problematic or colloquially, addiction even if it’s only one drink.