I suspect both may be interesting to study more!

Several existing studies I’ve seen have done things like prompt the LLM to produce a poem in a certain poets style, then ask people to spot the fake in a collection of poems, which they aren’t great at. This is, I would argue, an extremely different context than what most of us are encountering AI text in, and the people sending me text aren’t prompting it stylistically like that.

On your second question, I definitely feel like I can tell the first time a coworker sends me AI text masquerading as their own thoughts, even if they had previously been opposed to such a thing. So it could be that familiarity is more important than my prior on whether they’d use AI? But interesting to think about either way