Blood Brain Barrier said:
It may turn out that recognizing a non-existent "self" is the ultimate sign of un-intelligence. Is there a self, really? We became aware of one, as the story goes, but that doesn't establish its existence. Science hasn't established its existence either: in fact just the opposite - that every part of us and every mechanism depends on some other part outside of ourselves. The line between inside and outside hasn't been drawn anywhere else than in our imagination, so the animals may very well be smarter in failing to believe that there is such a line.
While the notion that animals are secretly smarter and that distinguishing self is bad may be relevant in philosophical, PETA and some religious (primarily Buddhist) circles, it really isn't all that functionally applicable anywhere else. Just as most people would appreciate religion be kept out of science, so too should we desire a barrier between philosophy in any kind of formative sense. Until such a day as someone actually develops any kind of evidence for such a nonsensical statement (nonsensical scientifically, not inherently like in some of the circles I mentioned) I will continue to believe that the beings capable of even postulating the notion that maybe they're wrong about in-depth philosophical questions of self are the more intelligent species. Let me also point out that any beings like animals that have failed to recognize a non-existent self would also prove worthless for all of our intents and purposes unless it's some crazy intelligent but otherwise incapable of self analysis creature.
We really just want beings that we can communicate with. That have a culture and a high enough level of understanding that they can actively teach us things and perhaps even learn from us. Finding a six-legged alien tiger on a distant planet that doesn't understand self anymore than a four-legged tiger here would be interesting but functionally no different than finding the exact same creature here on earth.
FYI, if you're coming at this from the Buddhist tradition then they make no claim that animals don't also fall prey to the "illusion of self". You're also incredibly wrong that science hasn't distinguished between self and outside entities. Almost every area of science routinely observes that things which impact one body regularly do not impact another except when some causal link is present. The Dalai Lama's ethics for a new millennium states that we are all subsets of a set and then makes the claim that since we are all members of the same set we are hurt when the set is hurt (aka, another subset is damaged/removed). But this is a fundamental flaw in logic to support a religious concept. If I have a bag of marbles and remove a yellow one and smash it, the blue ones are not somehow now damaged or really impacted in any way. The set is impacted but not all of its individual components. I should mention here that I specialized in Tibetan and Himalayan religions. So you may feel free to respond with any traditional rebuttals or anything like that. But I apologize if you weren't trying to approach it from this route. It's just highly unlikely that you'd have come to this method of looking at it in the absence of Buddhist religion and philosophy.