[rory]

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.

[tux3]

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

[alistairSH]

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.

[hanniabu]

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.