>What exactly are they meant to replicate other than other IQ tests?

if a variety of different IQ tests sort the same people the same way, even though every question on the tests is different from the other tests, you have shown that the test is showing something about the subjects, not something about the tests. and that is replicable, and falsifiable.

if you follow the same people over time and provide them with new tests, and they continue to sort in the same relative fashion, you have increased confidence that you are measuring something relatively fixed, not variable. For statistical significance (look it up) you don't draw conclusions on the basis of one person (or one Dad) but on population samples tested under standard conditions.

this is like all study results published here, a thousand nerds who've never studied intelligence come up with a hundred objections to what was tested, assuming with arrogance that the people who specialized and did the work aren't considering what comes off the top of this nerd's head. Better qualified nerds did this work.

>Myers-Briggs...'s obvious horseshit

Myers Briggs is not complete horseshit, correlates closely to, but not as good a fit as, the generally accepted Big Five Factor system, the gold standard of personality tests: you should educate yourself a bit more. Myers-Briggs essentially tries to phrase everything in a postive way, where the Big Five separates and includes Neuroticism which is a more negative (for the person) trait. All these traits should be considered adaptive till proven otherwise, so resist the urge to judge.

The Big Five --- not all that great either!

https://www.stat.cmu.edu/~brian/Pmka-Attack-V71-N3/pmka-2006...

(1st section).