As two women with no formal psychological training, Myers and Briggs serve in stark contrast to other psychologists of the early 20th century; however, their fierce devotion to the gospel of personality revolutionized psychological assessment.

Myers-Briggs’ evolution into the personality gospel

Source: Myers-Briggs’ evolution into the personality gospel | The McGill Tribune

Opinion – Any kind of personality classification will only include elements that the test designers understand, appreciate or perhaps believe in. This experimenter bias is unavoidable. That’s why I steer clear of test and labels. Often they present a caricature of the full person. And in some instances, I think they impede rather than facilitate growth.

The discoveries and achievements purely in the fields of psychology and psychiatry are not capable of offering a truly complete vision of the person. They are not capable of resolving on their own the fundamental questions concerning the meaning of life and the human vocation.

St. John Paul II