I’ll just leave my comment from further down in the thread here for you two:

I don’t like MBTI either, they’ve had a hundred years of opportunity to do science but never used it. They’re a business selling coaching re-investing into marketing, not science. I’m merely using their abbreviations because they became a lingua franca.

MBTI being bunk doesn’t mean that Jung didn’t spot something real, though, even if he proved nothing and could only describe it fuzzily (he didn’t even describe 16 types, but eight, based on primary cognitive function. In that rough model ISTPs and INTPs are one and the same which we definitely aren’t). The whole of Psychological types is basically saying “hey guys there’s something here we should have a look at it”. Chapter 10 is the interesting one, the rest is… philology? It’s the best proof he could muster back then give the man a break that was 100 years ago.

On the scientific front the best the typology community has right now is Juan E Sandoval’s stuff, the pilot studies are quite promising but there’s more theorycrafting to be done before applying for grants for properly-sized studies to then throw at the scientific establishment saying “prove us wrong”.

In case of tl;dw: Consider embodied cognition, and following from that that cognitive operations are expressed outwardly by various gestures, suchlike, CT calls the lot of it vultology. Then make a taxonomy of markers, analyse a lot of video marking those things and throw statistics at the data, what you get out of that is bimodal distributions, showing that there’s actual differences between people (that is, unlike Big5 axis which don’t have bimodal distributions). Make a twin study, observe that twins share vultological clusters, strongly suggesting that those clusters are innate. Flank by psychological questionaries establishing correlations between the vultological clusters and self-reported cognition.

You can say that you’re sceptical but if you say that that’s not doing science then I don’t know what to tell you, either.