Yes, I think unfamiliarity might actually be the main explanation here. IQ tests in general were popular 20 years ago and have since fallen out of fashion quit

Yes, I think unfamiliarity might actually be the main explanation here. IQ tests in general were popular 20 years ago and have since fallen out of fashion quite significantly: https://trends.google.com/trends/explore?date=all&q=IQ%20test https://trends.google.com/trends/explore?date=all&q=IQ%20tes... The lower performance may simply be due to people being less familiar/trained on the type of questions that IQ tests tend to ask.