https://www.tumblr.com/lizzie-queenofmeigas/822137805619724288?source=share
People don't read even AGOT
"It wasn't fair. Sansa had everything. Sansa was two years older; maybe by the time Arya had been born, there had been nothing left. Often it felt that way. Sansa could sew and dance and sing. She wrote poetry. She knew how to dress. She played the high harp and the bells. Worse, she was beautiful. (...) It hurt that the one thing Arya could do better than her sister was ride a horse. Well, that and manage a household. Sansa had never had much of a head for figures. If she did marry Prince Joff, Arya hoped for his sake that he had a good steward." Arya I, AGOT.
Arya is 9. Sansa is 11. Sure they are children and things change. But is clear that Arya has more aptitute towards natural sciences (she also has knowlege of plans which we see in her time in the Riverlands) while Sansa has more aptitute towards the Arts. Also, by her time in Braavos she knows 4 languages and is going to learn 2 more.
This is not to say one things makes you more inteligent or capable. Our society already tends to think only those who study natural and formal sciences to be more intelligent.
That being said, Arya clearly is more educated which is interesting considering Sansa is the one who is at various court all time, and it would be something interesting do meta about. How George is exploring education formal, informal, and non-formal.
They are just different. Sometimes I think people like this didn't grew up with siblings, cousins or you know, other kids they age.
I also saw many say that Sansa has an exceptional memory (compare to Arya) because she knows the heraldry of Westeros.... But so those Arya (the show just made it seem like not because Arya in it doesn't known the House Mooton banners). They knowing the banners is also not a show of who is clever because the pov structure and George needing to name houses.
The point of this is that people are different and have different type knowlege.. but sometimes even in a group of intelligent people one or two stand out. Like Missandei. I hate how the fandom uses education in their Arya vs Sansa vs Dany arguments when little Missandei is there. Missandei is the genius of asoiaf. Even as a child (11) and if not a slave prior to Dany freeing her, I have no doubt she would be on par in adult Tyrion and Sam. But you never see people who use the intelligence/reason argument for rulership speak of Missandei... I wonder why 🤔🙄
Most of the characters are very intelligent in some capacity. Dany speaks a lot of languages and is s military commander despite having no formal education, she is also able to piece magic and dreams together which is an intelligence on the occult few others have.
Arya also speaks various languages and is quick on her feet in survival situations, which is why she makes s good leader to her little group despite being so young.
Sansa is better at arts, dancing and sewing and playing the harp.
Missandei is very good at languages and also shows a knowledge of the world and how it works at such a young age that is a wonder.
That being said, intelligence is hard to quantify. People have different knowledges on different things, so you might speak to anyone who is "smarter" than you or more academically inclined and in certain topics you know more or understand better.