THEY CAN'T REPLACE CHILDREN EITHER:

Who's the dummy? (Helen Pidd, September 11, 2006, The Guardian)

The trainers at Boudewijn, along with much of the dolphin-loving world, are deeply unimpressed with claims made by Paul Manger, a 40-year-old professor of neuroscience from the University of Witwatersrand in Johannesburg. In a weighty scientific paper published earlier this year in the Biological Reviews of the Cambridge Philosophical Society, Manger hypothesised that "there is no neural basis for the often-asserted high intellectual abilities of cetaceans." In other words, despite their supersized brains, cetaceans (whales, dolphins and porpoises), are profoundly thick.

This claim flew in the face of almost everything else published about the mammals recently and, indeed, ever. Which is why people are so touchy about it. "No one I have talked to in the scientific field takes the claims Manger makes in this paper seriously," snaps dolphin expert Lori Marino, senior lecturer in neuroscience and behavioural biology at Emory University, Atlanta.