The thread title is pretty misleading as @Data10 points out. The SAT and ACT averages, 25-75 show that the majority of the 36/1600 end up at highly selective colleges. Take Stanford, the enrolled SAT math 25/75 is 720-800, so off the bat you have 25% of the enrolled class with 800, the CR is 700-770, so quite a few 800s there, not as much as for the Math section of course, ACT 25/75 is 31-35, quite a few 36s there. And this applies many other colleges as well, but the fact is that there are a lot of perfectionists walking around Stanford, if you define that as getting a 1600 or 36.
The 1590-1600 is a different issue, as others have pointed out, but a 1600 or 36 in one sitting will be read well.
I don’t think that admissions officers prefer 1570s or 35s to perfect scores. I think it’s just that most people acknowledge that scores of 1570 or 35 show that the person’s standardized test scores are plenty good, that box is well-checked, move onto evaluating other components. It’s not as if any admissions officer would deliberately rank higher an almost perfect score over a perfect score, all other elements being equal.
Once scores get into that almost perfect range, it definitely makes sense to spend time on other components of the application, rather than cramming for yet another attempt at the SAT/ACT.
It would depend on what you mean by deficit, by and large, perfect scorers don’t have too many deficits, which is why they’re at places like Stanford, Harvard, MIT et al. Caltech’s ACT 25-75 is 35-36, which probably means 25% 34, 50% 35 and 25% 36. Unless you have a hook, you’re not applying to Caltech unless you have a 800 or 36 in the math sections. Again, Caltech looks more at how you do in the AMC/AIME than SAT, because that gives them and colleges like them a better idea who the stronger math students are.
Caltech was test blind for the class of 2025 and has committed to continue being test blind for the future classes of 2026 and 2027, so they aren’t looking at SAT score at all. Considering they had a 62% increase in number of applications upon going test blind, I expect a good number of persons who felt their scores were subpar for Caltech chose to apply.