"SAT scores are predictive of IQ" is not the same as saying "if an individual gets a higher SAT score than another person they have a higher IQ than that person

"SAT scores are predictive of IQ" is not the same as saying "if an individual gets a higher SAT score than another person they have a higher IQ than that person". If however you had a group of 100 people that had a fairly higher score, it is very likely they would have a higher mean IQ than a group of 100 people with a lower score. Nor is it the same as saying "the SAT is a perfect IQ test". A perfect IQ test, one that gives an individual the same score every time, and ranks everyone along an unquestioned scale, is likely impossible.