The SAT is one of those very important, seminal tests that measures aptitude and intelligence which is especially pertinent for those students seriously considering going on to college. The roots of the SAT began back in the 1930s and early 1940s, to which its popularity and need for college admissions and eligibility increased significantly over time so that the SAT test score soon became the score for high school students to master, and to demonstrate their worth.
While it isn't surprising that test questions have changed over the years, it is surprising that the amount of time given to answer test questions has also changed from year-to-year, additionally an essay section was added to the SAT but later dropped as a requirement to it, and it is especially surprising that test scoring itself has changed from year-to-year. All of these changes, means in effect, that a SAT score for somebody in 1950 is not equivalent to the exact same SAT score in 2015. Perhaps that is the way it should be, that is that testing evolves and changes over time, but one can make a very strong argument that the true purpose of the SAT or any testing for that matter, should be to measure the mastery of certain subjects such as math and reading, and the requirements for that demonstration of mastery, should be fairly constant and not in a state of flux.
What a lot of people, may not recognize, especially parents that recall their own SAT scores from back when they were in high school, is that the SAT board, for spurious reasons, decided that in April of 1995 that SAT scoring needed to be "recentered". Of course, in America, you can always count on words being utilized and applied in ways that seem to obfuscate the true meaning of what is going so, such is a word like recentered, to which those giving the SAT scores, decided that since SAT scores were in a dramatic freefall, and because they felt that the true center or average for a given SAT score for those taking it, should be 500, they changed the scoring of such, to reflect that desire. This means, for a parent comparing their pre-1995 score to their child's post-1995 score, that comparison will not be between apples and apples, since scores have been uplifted since 1995. For instance, in 1992, the average math score was 476 and the average reading score was 423, whereas in 2015 the average math score was 511 and average reading score was 495. To the unaided eye, it would appear that students had gotten appreciably smarter since 1992, but in fact, those scores, once the recentering bias is removed, are in fact, not meaningfully different.
The long and short of it is, that the SAT scoring, test questions, and time allocated for such, have changed so meaningfully and been distorted by design that a grand illusion has been foisted onto the American public, to which this illusion purports to show that American high school students are smarter than their parents. Unfortunately, that isn't true at all, at best today's high school students aptitude and intelligence are equivalent to their parents and at worst they are a sad reflection of the greatest generation and their progeny.