Self awareness is considered to be a faculty of those animals which are at the top of the 'cognitive hierarchy', and is almost synonomous with presence of what could consider as intelligence (in animals anyway), not to mention its implications for consciousness. So what animals exhibit self-awareness? In this paper by Plotnik et al (PNAS, current issue), the possibility of elephants (in this case asian elephants) displaying self awareness was examined. They used the standard mirror test - a cross (or mark) is placed on the animal in a location where it would be impossible to see without the aid of a mirror (in this case above one eye). When a mirror is present, animals displaying self-awareness would (eventually) realise that the thing it sees in the mirror is itself, and thus examine the foreign mark on its own body, and not on its reflection. See paper for further details.
What was found was that a single elephant displayed this self-aware behaviour, out of a group that was tested. Not so impressive at first blush perhaps. But when it is considered that only around half of monkeys tested using this procedure display self-awareness, the results of this study carry more weight. Previous to this study, self awareness was considered to be the domain of humans, monkeys, and dolphins. The behaviour of the elephant in this study was comparable to the behaviour of these other animals.
In the discussion of their results, the authors suggest that self awareness capabilities may be indicative of a clear distinction between self and other, which would be necessary for social interaction. Thus the suggestion that convergent cognitive evolution has occured in these species: that the 'property' of self awareness for an agent may be emergent from the need to interact socially. In other words, social interaction is a driving factor for cognitive evolution, to a large extent if these results are to be taken into account. This would have huge implications for the study of consciousness, in both biological and artificial systems. If self-awareness is considered to be a basic type of consciousness, then the possibility arises that the only reason consciousness emerged was due to the development (perhaps through other evolutionary driving factors) of social interaction networks and hierarchies.