The definition for intelligence changed over the last 2 centuries because we keep discovering how an animal can fit the definition, and intelligence was used to separate humans from animals. Now it's even worse because people are trying to separate AI from humans.

I like the concept laid out by Delany: in a novel he describe 3 levels of intelligence based on the understanding of various point of views, but it's not a ranking.

The first stage is simplex: people don't understand the science of the world, so everything is kind of magical but this concept of magic make the world hold itself and they can grasp everything and use everything with this conception of magic.

Second stage is complex: people have an understanding of science and they can explain many things, but not everything. And when they can't explain something, they can't cope with it, because they don't have the conceptual tools for it. Thus they will either deny this thing existence of plug it into their existing concepts by ignoring the feature that can't fit.

Third and last stage is multiplex : people can accept that there are theories different than the ones they know, ideas also. Point of views can shape the way you see the world, and even the scientific theories you have to explain the world can be seen as a point of view on the world, so changing this point of view can bring a new or different understanding of a phenomenon or thing or person. These points of view all coexist at the same time, none of them is more true than the other. Like the concept of magic, this allows to grasp, use or accept even the ununderstandable and the unknown, but with a better ability to understand than the simplex stage.

I like this model. But it's more a model for open-mindedness than intelligence. But maybe that's the thing.