[User9821]

My dog never saw a mirror in his life, he lived outdoors, and aside from a puddle, he would never have an opportunity to see his own reflection. One day I had a fullsize mirror outside. I walked my dog infront of it, pointed to it, tried to hold his head to look into the mirror, and there was absolutely no reaction. It's like my dog was looking into an empty wall. It wouldn't make eye contact with the reflection, it was simply like it didn't exist.

So, what's going on here? My dog would go crazy if another dog was anywhere within view, but nothing happened. Did my dog just understand without doubt that's a reflection, that dog is me, that human is you, there's no point in even looking at it for a second? Or did my dog just recognize it as a 2D surface, and think anything in the mirror doesn't exist, it's just a bunch of shapes moving around. Kind of like holding out a printed photo of a dog, where it would just see a blob of color on the paper, recognize there's no dog here, nothing physically present, no depth, no smell, no noise, etc.

[TwoBit]

I have this theory that some animals (e.g. cats and dogs) do in fact recognize that mirrors are reflections, but they just don't care about what's in the reflection. We are fascinated by the idea that we are watching ourselves, but that's a somewhat meta concept and animals just don't care. Just because an animal doesn't care about reflections doesn't mean it necessarily feels like it needs to rub red paint off its reflected self or even really make that connection.

[simonster]

This seems right. I work with monkeys, and some of our monkeys have mirrors attached to their cages. They don't use the mirrors to inspect themselves, but they do seem to use the mirrors to surreptitiously spy on other monkeys. It's likely that a monkey can quickly figure out that the thing in the mirror isn't another animal and when they move, the thing in the mirror moves, but drawing the connection that they are the thing in the mirror seems quite a bit harder.