It's an interesting point - it may be possible to have 'impostor syndrome' syndrome, where you think you have imposter syndrome but you're actually an imposter. According to the study, if you were an imposter you'd have to be incompetent which means you'd be unable to judge that you were incompetent and you'd rationalize that you were competent.

Terrible cycle, but it's according to this article if you were an imposter you'd probably think you weren't. Uhm. This probably isn't helping. Good luck with your imposter syndrome!