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Sorry to disappoint you three, but it is utter crap. It is mainly used in North-America. Very few practitioners and practically no scientists and universities use it in Europe. The practitioners which use it are usually coaches and they can use it successfully, because it really markets very well. It leaves a first impression of validity, it seems reasonable, it is wonderful to be able to combine 4x facets so easily, to assign you to one rainbow-color.

You don't get 4 traits in testing and literature though. It's either three (PEN) or (big) five (OCEAN) (big six doesn't seem to be too big of a topic anymore but I could be wrong).

It's even in the press. Type myers briggs and unreliable/unreliability and you'll find tons of articles, some directly referencing scientific papers.

Just examples:
https://www.psychologytoday.com/us/blog/give-and-take/201309/goodbye-mbti-the-fad-won-t-die
https://www.forbes.com/sites/toddessig/2014/09/29/the-mysterious-popularity-of-the-meaningless-myers-briggs-mbti/#4475c12b1c79
https://thoughtcatalog.com/lorenzo-jensen-iii/2015/05/13-reasons-why-the-myers-briggs-test-is-absolute-nonsense/