American IQ scores have rapidly dropped, proving the 'Reverse Flynn effect'
When IQ tests were invented folks didn't know about tests, at least in the US. They were rural immigrants who could maybe read. So when asked logic questions, they would answer pragmatically and be 'wrong'. That had some impact on perceived early low results.As folks became better-read and educated they began to understand that IQ test questions were a sort of puzzle, not a real honest question. The answer was expected to solve the puzzle, not be right in any way.E.g. There are no Elephants in Germany. Munich is in Germany. How many elephants are there in Munich?  A) 0  B) 1  C)2Folks back then might answer B or C, because they figure hey there's probably a zoo in Munich, bet they have an elephant or two there. And be marked wrong.