Self-awareness. A lot of philosophy has been built up around this term. Self-awareness is the ability to recognize the self as distinct from the environment. It is having consciousness and knowledge of the self as an individual. Humans certainly have self-awareness and we are able to recognize our body, our feelings, and our thoughts as our own. A lingering question has pursued humanity for generations: Are we alone in our self-awareness on this world, or might other animals have a sense of self too?

The Mirror Test

Courtesy of roseoftimothywoods65% of human infants can recognize themselves at 20-24 months of age. — Courtesy of roseoftimothywoods
65% of human infants can recognize themselves at 20-24 months of age.

The mirror test is a technique that was developed to test self-awareness in animals. In the mirror test, animals are marked in such a way that they cannot see the mark without a mirror. When presented with a mirror, most animals either do not respond or react as if their reflection was another animal instead. However, some animals respond differently when viewing themselves.

A small number of animal species are capable of recognizing themselves in a mirror. They use the mirror to examine the mark on themselves and often touch the mark curiously after identifying it. These animals are demonstrating self-awareness. To be able to recognize oneself in a mirror, one must have a rudimentary sense of self. These animals may not be able to wax poetic about the nature of existence, but they certainly seem to understand that they exist.

Apes

Chimpanzees, bonobos, and orangutans have all passed the mirror test. These are some of our closest relatives in the animal world, so it is perhaps unsurprising that their cognition ranks among the highest. Curiously, gorillas have shown poor response to this test. One particular gorilla, the sign language-speaking Koko, has been able to recognize herself in a mirror. It has been suggested that the poor performance of other gorillas is a result of the general gorilla habit of avoiding eye contact with members of their own species, leading to them spending less time examining the mirror.

Elephants

Elephants are undisputedly among the most intelligent animals in the world. Their brains show physical evidence of this: They have the largest temporal lobes in proportion to body mass of the entire animal kingdom. Not even human temporal lobes can match an elephant’s. The temporal lobe is home to many of the functions that we usually link with intelligence: Cognition, communication, language, and spatial memory.

Elephant behavior supports this diagnosis of high intellect. They are adept at cooperating to solve problems, using tools, and maintaining complex social relationships. Asian elephants have passed the mirror test and new research is constantly shedding light on the thought processes of these incredible animals.

Dolphins

Dolphins are the geniuses of the sea. Bottlenose dolphins and orcas (Orcas are dolphins, not whales) have both been able to recognize themselves in mirrors. Bottlenose dolphins have shown a number of fascinating behaviors in the wild that demonstrate their cleverness. Over the last ten years it’s been discovered that bottlenose dolphins each have their own names and that they are able to remember and call other dolphins by name as well. A dolphin’s name is called its “signature whistle.” Dolphins adopt their signature whistles early in life as variations on their mother’s whistle.

Birds

Previously, I’ve blogged about the amazing intellectual ability displayed by birds. Only one bird thus far has passed the mirror test, the Eurasian magpie. Magpies, like their astute crow relatives, are in the family Corvidae. Magpies were able to locate a sticker attached to the bottom of their beaks when given access to a mirror, showing self-recognition. Many corvids use tools and display complex social behaviors, so it’s not surprising that magpies are self-aware. It is the birds that didn’t manage to pass the mirror test that are more perplexing.

Thus far, African grey parrots have not passed the mirror test. The brilliance of these parrots is undeniable. Dr. Pepperberg’s research program with Alex the African grey parrot showed that these birds have a cognitive ability on par with a 4 – 6 year old child, can learn up to 100 words, and can identify objects by color, material, shape, and number. It could be that parrots are not self-aware as it is currently defined, or maybe we just need a different test to measure it with.

Insects

Courtesy of Andreas WeggelAnts of the genus Myrmica were tested for self-awareness. — Courtesy of Andreas Weggel
Ants of the genus *Myrmica* were tested for self-awareness.

Insects aren’t usually thought of as especially brainy, but some have actually passed the mirror test! Ants were first placed on one side of a glass with nestmates on the other side. Ants under this condition behaved unremarkably, taking little notice of the other ants. Researchers then marked the ants on the head, either with a blue dot or with a brown dot that blended in with their natural color. Painted ants without a mirror ignored the marking. However, when the ants were presented with a mirror, the blue-painted ants took notice.

The blue-marked ants attempted to clean themselves after looking in the mirror while ants with brown dots did not. However, all ants behaved unusually when in front of the mirrors, moving their heads and antennae about rapidly. This is a very curious result indeed. Ants are social insects and are capable of learning and carrying out complex actions, but they are not usually regarded as intelligent. This result begs the question: Is self-recognition the same thing as true self-awareness? Science does not yet have an answer.

Beyond the mirror test

Pigs are as intellectually complex as dogs and apes on some measures.

There are many highly intelligent animals that either have not yet been given the mirror test or have failed to pass it. While the mirror test is a useful tool for examining animal self-awareness, it is imperfect. It fails to account for animals with social conditioning that make them interact more poorly with the mirrors, such as gorillas. It also relies on animals using vision to identify themselves. Dogs are capable of some impressive intellectual feats but rely more on hearing and smell and have not yet passed the mirror test. There are a lot of places that future research could go, and a lot we still have to learn about our animal neighbors!

- Kate Dzikiewicz, Paul Griswold Howes Fellow