Yes, Douglas Adams got there first:
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.
This article available online at:
http://www.theatlantic.com/daily-dish/archive/2008/01/the-brains-of-whales/220894/
