How people get perfect scores on SAT/ACT without studying?

I was wondering how some people get perfect score on SAT?ACT without even studying. IS it just like using you common sense, or does it depend on what school you went to, and the education you received?

For R and W it depends largely on your history as a reader. Kids I know who can get top scores before or without studying have invariably been voracious readers.

My brother is a math genius. He got perfect scores on the ACT, SAT and GRE math sections, without studying. I think for math you have to be a natural. Us regular humans have to study.

My kid is a voracious reader and got 36 on English and reading sections with barely any prep. Did prep for science and math by taking those sections only at home about 5 times. Strictly timed. Got 33 math and 36, science for a 35 composite. 1 more math question right would have been a 36.