Well it’s just science. Though there is a difference between logical and rationa

Well it’s just science.
Though there is a difference between logical and rational, in that rationality can include subjective choice, and logical can explain subjective choice, not argue it.
At some point the principle difference in intelligence results in error detection. As you get smarter your ability to learn concepts of increasing abstraction and more so with multiple states in working memory, improves marginally. But if you look at human performance it tends to result largely in error detection, more so than any increase in innovation.
Conversely, the most visible sign of decline in intelligence other than knowledge and sentence content, formation, and length, is logical incompetency.
Logical competency declines rather rapidly under 100-105 to where simple negative logic (just like neural nets fail to perform) is overwhelming for the individual.