This seems like an incredibly strong claim presented without evidence (unless you believe in fairly debunked "skills are fixed at birth" nature-vs-nurture ideas

This seems like an incredibly strong claim presented without evidence (unless you believe in fairly debunked "skills are fixed at birth" nature-vs-nurture ideas). The vast majority of pedagogical literature and science from the last couple of decades is talking about the importance of instilling a "growth mindset", depicting a whole zoo of interventions shown to improve cognitive skills in students, including as measured by SAT scores and IQ tests (even if they are imperfect measurement tools). There is a relatively easy way to disprove your claim if you believe in IQ tests (an assumption I am making). You can improve your test score by practicing on similar tests (or even unrelated things like crosswords). Trivial exercises can improve your IQ test score or any other cognitive measure.