I think they're just explicitly stating what the OP implied. And I think it's a worthwhile thing to point out: IQ isn't the be all and end all and just because you're "high IQ" that doesn't mean you've above persuasion or something.

True, but susceptible in different manners. As for a source which appears “trustworthy”, such as an LLM spewing out data, low IQ are more susceptible as per this study

https://www.researchgate.net/publication/325733310_The_Influ...