What is intelligence? I don't know. I think maybe we need as many words for it as the proverbial Eskimo has for snow. Remembering things is intelligent. Managing your life is intelligent. Being able to make people understand you is intelligent. Being able to train a dog, that's pretty intelligent. I'm intelligent if you count having a PhD as being intelligent (and I think that is true for a certain value of intelligent) but in some ways I'm very stupid -- I'm nowhere near as good as my brother is at being happy, I struggle to feed myself healthily and inexpensively, and I can't play chess or do cryptic crosswords. This is one of those philosophical problems that spills out into real life. The other day I was talking about atheism and the idea of "Oxbridge" intelligence came up, as a type of intelligence that often involves a certain type of stupidity. As someone who has sat in a gown at High Table and had my blouse's label politely tucked in by a member of the waiting staff, I can't claim not to be implicated in all that, though as a concept it does a disservice to the fact that there are plenty of people at Oxbridge who are actually fully functioning members of society. I can think of about five without even trying.
Yesterday I went to a lecture on Machine Learning, a sub-part of Artificial Intelligence. It was full of very complicated stuff which I couldn't follow. But the question "What is Intelligence?" was pretty quickly dealt with. Intelligence is the ability to solve problems, so that "we do in life better". (Oh dear, that rules out my PhD as a sign of intelligence, let alone reading War and Peace.) I also went to an Introduction to Artificial Intelligence this morning, which sensibly did not define intelligence, but looked at the different ways people try to replicate it. Some people do AI in order to learn more about animal and human cognition, by modeling it and seeing what happens.
So the people who are shaping our practical idea of what intelligence is, and what intelligence should be, are essentially taking it for granted that what intelligence is is what they are, and using that as the unreflective basis of their research; and yet these people are, for a certain value of stupid, quite likely to be very stupid. I find that interesting, in a worrying sort of way. It's not great news for people from cultural backgrounds which are under-represented in scholarly circles, for example.