Ben Ambridge at the blog of the Welcome Trust:
Previously it was thought that the magical ability which non-human species lack is the understanding that words can be put together in different orders to express different meanings. There’s a saying in journalism: Dog Bites Man isn’t news, but Man Bites Dog is. It makes sense only because we understand that the order of the words tells us who’s doing the biting and who’s getting bitten.
However, a few species have actually passed this test. On the comprehension front, we have Phoenix and Akeakamai, two dolphins studied at the University of Hawaii, who were taught a language in which the ‘words’ were different whistle sounds played by the trainer (and chosen to approximate dolphins’ own calls). The dolphins understood that, for example, “put the pipe on the hoop” and “put the hoop on the pipe” meant different things and were able to respond accordingly, even when the exact sentence hadn’t been presented before. Some apes, such as Kanzi, a bonobo raised in Atlanta, have passed a similar test although debate continues as to whether or not they can combine words – in this case hand signs – in their own communication (watch the 2011 film Project Nim to see this controversy played out).
The finding that some species do seem to appreciate the powerful combinatorial properties of language serves only to deepen the mystery. If these animals are so smart, why aren’t they explaining what it’s like to be a chimpanzee, or at least politely asking to be let out of the cage? Tomasello’s answer is that what they just don’t seem to get is that language is fundamentally cooperative, almost altruistic, in nature. You understand that, if I say something to you (“Look, there’s your boss”), I’m doing so because I believe you will find it useful or interesting. Tomasello’s big idea is that this idea of doing something for the benefit of someone else is completely alien to other species.
More here.