> Norwegian researchers analyzed the IQ scores of Norwegian men born between 1962 and 1991 and found that scores increased by almost 3 percentage points each de

> Norwegian researchers analyzed the IQ scores of Norwegian men born between 1962 and 1991 and found that scores increased by almost 3 percentage points each decade for those born between 1962 to 1975 Statements like this have always made me question these tests. Ten points in IQ represents a movement of one standard deviation in intelligence. To believe the quote above would mean that there was a massive increase in intelligence between the 1960's and the 1990's. But an increase of one standard deviation across any trait at a population level is very very unusual, and likely would have been noticed long before any studies were conducted. Put another way, do we really believe that someone with slightly below average intelligence in 1962, say an IQ of 85, is the intellectual equivalent of someone with a significantly below average IQ (e.g. 75) in 1990? An IQ of 75 typically means you're not in public school or if you are, you're in Special Ed.