Do dolphins recognize themselves in mirrors?

If you’ve been following the news lately, you might have seen a little story about elephants that can recognize themselves in mirrors. This is a rather major discovery for animal scientists – elephants now join dolphins as the only animals other than the great apes and humans that can recognize themselves in mirrors. Many scientists use the mirror self-recognition experiment as a test of an animal’s capacity for self-awareness – a trait often linked with cognitive complexity and intelligence.

The mirror self-recognition test was pioneered by Gordon G. Gallup, Jr. – a psychologist from the University of Albany. In 1970, Gallup contributed a ground-breaking article to the journal Science showing that chimpanzees were able to recognize themselves in a mirror. His experiment, which has been used in modified forms ever since, works like this: you first allow the test subjects a few days to familiarize themselves with a mirror. It is during this time that, if the animal is up for the task, it will come to realize that the mirror is a reflection of its own image. Most animals will display ‘social’ behaviors at the mirror – as if they were encountering another animal, but if the animal manages to catch on to the concept of a mirror, these behavior will stop. After the animal is familiar with the mirror, researchers will give the animal some kind of visible mark on its body. If the animal appears to inspect the mark on its body by using the mirror, then voilà – you have mirror self-recognition. This has been tried successfully on elephants, all of the great apes species (like humans, chimpanzee, gorillas and orangutans), and, of primary interest to this podcast, dolphins!

In 2001, Diana Reiss and Lori Marino performed the mirror self-recognition test on two dolphins at the New York aquarium. Similar to Gallup’s original experiment, the dolphins were marked with a temporary black ink after first having been exposed to mirrors. When marked, the dolphins twisted and turned and tried to look at the mark in the mirror – exhibiting behaviors similar to chimpanzees when inspecting their marks. In the 2006 study of elephants at the Bronx zoo, the elephants also spent a significant amount of time inspecting the marks in the mirror. The conclusion here: both dolphins and elephants can recognize themselves in mirrors.

So, what’s all the fuss about? Well if you have ever seen a cat, dog, or bird attack its reflection in the mirror, you will realize that figuring out what mirrors are all about is usually considered beyond most animals. But the behaviors discovered in these experiments might be the result of something more important than just an ability to figure out what a mirror does. Many psychologists think that recognizing yourself in a mirror is the first step in a chain of abilities that leads to a Theory of Mind. Theory of Mind is a psychological ability that works like this: I know that I have my own mind with my own thoughts, beliefs and desires and consequently you must have your own mind with your own thoughts, beliefs and desires. Having a Theory of Mind is a powerful thing – it allows an animal to predict and manipulate the behavior of other animals, something at which humans are fantastically good. It also leads to advanced social emotions like empathy. So if an animal like a chimpanzee, elephant or dolphin can recognize itself in a mirror, this might mean that it is aware (or conscious) of itself. If it’s aware of itself, then it may be aware that it has its own thoughts, which means it might also be aware that other entities may also have their own thoughts: a Theory of Mind. Of course, it might not mean this it all – it could simply mean that the animal figured out some basic properties of mirrors without making any giant cognitive leaps. This is currently a topic of debate in the field of psychology. These experiments have provided important pieces of this puzzle. It is probably an important fact that all of the animals that have managed to perform this test so far; the great apes, dolphins, and now elephants – are all large-brained social animals; the most obvious candidates for benefiting from a Theory of Mind, and self-awareness. No matter how you interpret it, the results of these experiments are certainly remarkable.