New Scientist – The Mirror Test

Horse looking in the mirror (Photo by Baragli, P., Scopa, C., Maglieri, V. et al.
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Dear Readers, every time we get a glimpse into the cognition of animals, it seems that we feel a need to raise the bar higher. So it has been with the Mirror Test. In a traditional Mirror Test, an animal is anaesthetised and then a mark is put on a part of the body that can only be seen in a mirror. When the animal revives, it will ‘pass’ the test if it investigates the mark, which scientists believe means that the animal recognises that it sees itself in the mirror, rather than another animal.

Animals that have ‘passed’ this test include great apes, one single Asiatic elephant, dolphins, orcas, the Eurasian magpie and cleaner wrasse, little stripy fish who pick the parasites off of larger fish. Animals that have ‘failed’ include sea lions, a wide variety of monkeys, octopuses and some birds that are renowned for their intelligence, including the New Caledonian Crow (famed for its tool-making abilities) and the African grey parrot (one of which, Alex, had a vocabulary of thousands of words and the ability to sort items into categories by colour or shape). It’s therefore clear that the Mirror Test is not a test of intelligence, but scientists believe that it indicates self-awareness.

So, to the horses. Paolo Baragli of the University of Pisa in Italy released 14 horse one at a time into an area with a large mirror. After an initial period of being aggressive to, or curious about, the horse that they saw in the mirror, Baragli reports that they started to do things like stick out their tongues and watch their reflections as they moved their heads from side to side. When a mark was put on their faces, 11 out of the 14 horses spent time trying to remove it by rubbing their heads.

Pretty conclusive, huh? Not according to the developer of the Mirror Test, Gordon Gallup at the University of Albany in New York. He disagrees that the horses recognised themselves in the mirror before the mark was put on, and none of them used the mirror to look at a part of their body that they couldn’t normally see. For Gallup, this is a fundamental part of the process, that is then verified by the use of the ‘mark’.

There have been many criticisms of the Mirror Test. For one thing, dogs don’t pass, largely because they use their sense of smell and hearing much more than their sense of sight. Cats, predictably, fail because they just aren’t interested. Pigs have passed a version of the test in which they use a mirror to find food, but don’t seem especially interested in looking at themselves. Gorillas have repeatedly failed the test, but this might be because eye-contact is seen as an aggressive act and so the apes tend not to spend much time investigating what looks like another gorilla at first glance.

Furthermore, even in animals where individuals display the ‘correct’ behaviour, others may not. Three Asian elephants were given the mirror test at the Bronx Zoo in 2006 – one of them ‘passed’ but the other two did not. This seems to me to say more about the personality of the elephants involved than their cognitive abilities or sense of self.

It’s very common for humans to set up parameters for a test which animals can then ‘pass’ or ‘fail’, without taking into consideration not only the inner worlds of the creatures being investigated, but their physical abilities and the environment in which they lived. I remember the view of Noam Chomsky, who maintained that humans were the only animals with language ability, and remained unimpressed by the chimpanzees and other great apes who were taught, and used, sign language in the 1960’s, even after the chimps started to make up their own nouns (Washoe, the most famous of these apes, made the phrase ‘water+bird’ on seeing a swan. We insist on dragging animals into our world rather than meeting them where they are, and looking at what’s important to them. Our science often shows a cataclysmic failure of imagination.

Nonetheless, it looks as if horses *might* have passed the Mirror Test, and so can be admitted to the pantheon of creatures who are self-aware. This is probably not, however, news to anyone who has spent any time with these animals.

You can read the whole article here 

6 thoughts on “New Scientist – The Mirror Test

  1. Anne

    This reminds me of Sylvia Plath’s “Mirror’ which begins:

    I am silver and exact. I have no preconceptions.
    Whatever I see I swallow immediately
    Just as it is, unmisted by love or dislike.
    I am not cruel, only truthful,
    The eye of a little god, four-cornered.
    Most of the time I meditate on the opposite wall.
    It is pink, with speckles. I have looked at it so long
    I think it is part of my heart. But it flickers.
    Faces and darkness separate us over and over.

    I thinks humans have different relationships with mirrors – some more close than others – and cannot help wondering if scientists make ‘human’ assumptions in these tests. The other thought that springs to mind is what do animals think of their reflection in the water when they drink – do they recognise that as an image of themselves?

    1. Bug Woman Post author

      Thanks for reminding me of the Sylvia Plath, Anne! And I’m sure some scientists do make ‘human’ assumptions. It’s so difficult to imagine ourselves in the shoes of another human being sometimes, let alone a completely different species.

  2. vuurklip

    Our little dog did a double take when she saw herself in a mirror for the first time – and then promptly ignored the mirror from then on. Obviously in my opinion because she recognised herself and was no longer interested: “It’s me, so what!”

  3. Clare Mcbride

    We continue to make progress if we find joy in asking questions

    Loved this report thank you

    Animals are influenced by everything, very hard to not say Eureka

    Forgive me for moving on from mirrors, these days I read of left/ right brain investigations of horses.

    Afraid I pay little attention to their conclusions

    Surely we can’t be confident with our findings unless we compare the work with horses who have only been handled/worked from the off side perhaps by left handed people


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