> I wonder if anyone has calculated a range of body sizes which maximise intelligence and the ability to exploit resources of their planet.
I don't think we understand intelligence well enough even on Earth to do something like that. For example, these spiders seem to have certain cognitive capacities beyond what a hippopotamus can do, even though the hippopotamus is obviously much larger. Even in a single genera, the intelligence of mammals or even just apes doesn't seem to scale with size or brain size.
There did seem to be some correlation between intelligence and the ratio of brain size to body size, but even that is not well established, and it is not clearly evident why it would matter. And, as others are pointing out, many studies of animal intelligence are actually deeply flawed, so perhaps we have just been measuring very wrongly.
I don't think we understand intelligence well enough even on Earth to do something like that. For example, these spiders seem to have certain cognitive capacities beyond what a hippopotamus can do, even though the hippopotamus is obviously much larger. Even in a single genera, the intelligence of mammals or even just apes doesn't seem to scale with size or brain size.
There did seem to be some correlation between intelligence and the ratio of brain size to body size, but even that is not well established, and it is not clearly evident why it would matter. And, as others are pointing out, many studies of animal intelligence are actually deeply flawed, so perhaps we have just been measuring very wrongly.