For instance, on the planet Earth, man had always assumed that he was more intelligent than dolphins because he had achieved so much -- the wheel, New York, wars and so on -- whilst all the dolphins had ever done was muck about in the water having a good time.
But conversely, the dolphins had always believed that they were far more intelligent than man -- for precisely the same reasons.
- The Hitchhiker’s Guide to the Galaxy
Yeah, I read it too, but let's not take the book as a holy one.
Dolphins are plenty smart, but their absence of a material culture also leaves them exposed to various forces beyond their control.
Are dolphin moms not grieving when their baby gets eaten by killer whales?
This sort of threats is ubiquitous in nature, but almost unknown in a civilization.
True nature is brutal.