Elephants can recognise themselves in a mirror

Self-awareness, as shown by the ability to recognise yourself in a mirror, is a trait shared by only the most intelligent animals. Humans, apes and dolphins can all do it, and now, scientists have shown that elephants can too.

You are on a date and by all accounts, it’s going well. Midway through dinner, you excuse yourself and head to the bathroom where to your chagrin, you see in the mirror that you have a streak of sauce on the side of your face. Embarrassed, you wipe it away and rejoin your date.

This is a fairly innocuous scene that some of us may have experienced ourselves. But it illustrates an ability that only humans and the most intelligent of animals possess – self-awareness.

Self-awareness is the understanding that you exist as an individual, separate from others. Having self-awareness is a vital step to understanding that others are similarly aware and have their own thoughts and desires.

As such, it is intimately linked to mental qualities like empathy and selflessness. This may seem obvious to us even human children only become self-aware in their second year of life.

In the animal kingdom, self-awareness is rarer still and has only been found in the most intelligent of species – humans, apes and recently, dolphins. To Joshua Plotnik of Emory University, the next obvious candidate was the elephant.

Elephants are highly intelligent and very empathic. They have been known to help each other and may even mourn their dead. Plotnik, together with Frans de Waal and Diana Reiss, set out to test for self-awareness in three Asian elephants.

The mirror test

The classic way of detecting self-awareness is to see if it can recognise itself in a mirror. All species begin by making the appropriate social gestures, and then start to inspect the mirror, often checking behind it to look for the stranger.

But a self-aware animals goes further – it starts to conduct repetitive tests, such as touching its face to see if the reflection follows suit. After a while, it starts to understand that the mirror image is itself.

Researchers test for this awareness by seeing if the animal can touch a mark on its body that it couldn’t otherwise see. And this is just what Plotnik did with three Asian elephants at New York’s Bronx Zoo.

The trio, named Happy, Maxine and Patty, were given a literally jumbo-sized mirror in their yard. An elephant uses its trunk like a human does its hand, and can touch most of their body surface with it. This makes them ideal for the MSR.

When the mirror was revealed, each elephant started to spend more time with it. They started to investigate the mirror and the wall it was mounted on with their trunks, peering behind or under it. As the days went on, they started investigating the mirror less and less.

None of them made any attempt to socially interact with their reflection and would do things like eating, that they would normally avoid when directly in front of other elephants.

They also started to make unusual body and trunk movements in front of the mirror in the same way that a person would check out a new outfit in a dressing room. They were clearly examining their own bodies, pulling their ears or sticking their trunks in their mouths, in a way that they never did without the mirror.

The mark test

At this point, Plotnik put the elephants through the mark test, by placing a visible mark on the right side of their heads, and an invisible control mark on the left side.

Of the three, only Happy passed the test. After being marked, examined herself in the mirror by moving in and out of view, and began to probe the visible mark with her trunk while ignoring the invisible sham one.

Even though Maxine and Patty both failed, Plotnik is not discouraged, pointing out that even in the frequently-tested chimpanzee, only one in two individuals pass the test.

The test will clearly need to be repeated in other elephants, but for the moment, this study provides compelling evidence that the Asian elephant can join the illustrious self-awareness club.

NB The history of mirror self-recognition is fascinating and is well beyond the scope of this article. While the test is undoubtedly useful, there is some debate about whether failing it proves that an animal is not self-aware. Gorillas do poorly in the test, but this may be because they see direct facial contact as a sign of aggression. Dogs tend to fail too, but their main sense is smell not sight.

Plotnik, de Waal & Reiss. 2006. PNAS 103: 17053-7.

Images copyright of PNAS Volumes 90-102, copyright © 1993-2005 by The National Academy of Sciences of the United States of America, all rights reserved. Volumes 1-89, copyright as a collective work only; author(s) retains copyright to individual articles.

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