What I find interesting on that page is that the more recent (past 2-3 decades) college preparatory tests (e.g. SAT) are not accepted as substitutes to IQ tests. Shows the trend of dumbing down the tests, I guess.
That is odd. If the tests were simply dumbed down, wouldn't Mensa just raise the required score? The implication is that these tests have become less IQ-correlated. I'd be interested to see a comparison in the type of questions from the 70s vs today.
Responding in a vacuum, but the other explanation could be that these tests fail to discriminate at the high-end. If everyone with a high score is squished together, raising the floor just amplifies relative noise
That's exactly what they did - they have 3 bands of years for the SAT. Two year bands (<1974, 74-94) are accepted with different scores, and the more recent tests (94+) are not accepted.
The major change in 1994 was the allowance of calculators during the math portion. I don't know why MENSA couldn't make a similar score adjustment here.
Probably less reliable and more overhead. You have to constantly evaluate what the new equivalent score and who knows, maybe even the max score isn't good enough anymore.