But two things are noteworthy here.
One, no one's ever replicated the study.
But more importantly, it misses the point.
The issue isn't whether some behavior can be learned.
It's whether a species has developed this ability spontaneously.
So what does the test tell us about corvids or chimpanzees?
For one thing, it is important because it sets animals with a sense of self apart from those without a sense of self.
But more importantly, many researchers believe that MSR is indicative of other advanced cognitive abilities.
Self-awareness, even in its earliest stages, might entail an awareness of others, the ability to see their perspective, to look at the world from another's point of view.
This is crucial, because it implies a high level of cognitive development.
It's perhaps the first stage toward the development of empathy.
But birds' brains are so small compared to primates.
True. Though corvids do have unusually large brains for birds.
But size isn't the whole story.
It's thought that primates are so intelligent because of a certain part of their brains, which birds simply don't have.
But there is an area in birds' brains that researchers believe governs similar cognitive functions.
So primates and birds' brains have evolved along different tracks, but ended up with similar abilities.