Looking around the room, nope, no bulging brains in sight...
The tests don't produce rocket scientists, just help find people most likely to be easily (read cheaply) trained for the job. At least that is the theory.
The only fiddling I attempted was to spend months doing "The Mensa puzzle book" and similar so I wouldn't be intimidated on the day, and approached the tests with a positive outlook.
A bloke I know answered all the psych questions (300 of 'em) "don't know", figuring they couldn't mark him wrong. They did.
The bullsh@t doesn't stop during the course either. Some people bristled at it all, I just thought of the whole process as a progression of meaningless "hoops" I had to jump through in style to ultimately do the job I wanted.
Whether I was to be eliminated at any stage was a possibility I refused to take seriously. When it has happened to others, they may be indignent at the slur on their character and career dismemberment, but you can usually see why it happened.
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"Station calling Centre, grow a head..."