Quotes from David B. Stein

We now enter the Twilight Zone of psychology. Hundreds of theories of personality exist, but no one has yet successfully identified, or even defined, what personality is (Hall and Lindzey, 1957). Thus, there exists a myriad of psychological tests that measure something, but no one seems to quite know what it is.

All of this begs the questions as to why psychologists are wasting so much valuable training time on arcane, unproductive, invalid, unreliable, and inaccurate courses.