I've recently heard a podcast by mr Flynn, the discover of the Flynn effect. According to him, populations worldwide are gaining about 3 points of IQ with each generation, but the kind of their intelligence is changing from more "down to earth" to more abstract. For example, he mentions how in 1920s, people in Siberia could not or would not answer the question like "What color are bears on the North Pole?", because they have never seen one and all the bears next to them were brown. Flynn suggests that their thinking was much more down to earth and practical.
I'm interested if "danger, coffee may be hot" and such warning labels a by-product of American legal system, or are indeed indicators of change in the quality of intelligence of the general population? Do "dumb warning labels" exist worldwide?