They all knew their native languages and had enough critical thinking to be accepted to college. SAT/ACTs include math and writing sections. So I would venture all 18-23 year olds accepted to college can learn a language and think critically.

Critical thinking helps kids get accepted to college? It sure didn't help back in my day.

I should have said, few are capable of learning a new language without total immersion. And few are capable of learning to do linear algebra, calculus, or C++ well. Even fewer are capable of serious critical thinking.

But they can still mostly benefit from college.