“We need better experiments to find out what dogs know”
Dogs don’t recognise changes to their own appearance – the ‘mirror test’ of intelligence. But as dog cognition expert Dr Alexandra Horowitz explains, there’s a reason they fail
Why is self- recognition a sign of intelligence?
Self-recognition comes out of the comparative cognition field, where people test if non-human animals can problem solve, imitate or learn, just as we would ask of children. Some questions are about meta- cognition – thinking about thinking. One meta- cognitive skill is ‘theory of mind’ – the realisation that others have minds different from your own, and know things you don’t. Humans gain this skill after about the age of three.
What is the mirror test?
This involves looking at yourself in the mirror and recognising that something has changed. The story goes that [psychologist] Gordon Gallup was shaving, and wondered if his captive chimpanzees would look in a mirror and see themselves the way he did. So he put a mirror in their enclosure. They attacked because there was a chimp running at them, but they soon learned and started to examine themselves. He surreptitiously marked chimpanzees on the forehead with an odourless red dye and recorded their behaviour the next time they saw their reflection. His chimps touched the mark on their own head, not the mirror, and tried to smell the dye on their fingers. That was considered passing the mirror self-recognition test.
Which animals pass the test?
Dolphins have passed using marks on their sides and a reflective surface in their aquarium, moving their bodies in unusual ways to see the mark. One African elephant passed the test and magpies have passed. But a number haven’t passed, like rhesus macaque monkeys. Dogs don’t pass the test. But think about differences in sensory equipment and what’s important for animals – whether they live with others, their social organisation, whether they groom themselves. All seem relevant to whether one might pass. With dogs, you have not a visual but an olfactory [scent- driven] creature.
So how did you test dogs?
I looked at a natural dog behaviour: they urinate, leaving information in their pee. They also sniff other dogs’ urine markings, so something is communicated, presumably about identity. They’re interested in who else is around. So I designed an ‘olfactory mirror’. I collected urine from 35 dogs and put small
amounts of the urine into canisters with air holes, then exposed the canisters to the dogs. The dogs spent less time sniffing their own urine and longer sniffing other dogs’. But then I took their odour and added anise (the scent of liquorice) to it. Sure enough, they spent more time sniffing their own odour with this mark.
So are dogs smarter than we think?
We have to take seriously what it’s like to be an olfactory creature, and how that revises what their cognition might be. It’s possible that dogs have a thorough understanding of themselves. Simply the fact we haven’t been able to answer these questions previously shouldn’t lead us to assume that dogs don’t have the capacity – we just need better experiments to find out what it is that dogs already know.
ABOVE: Dogs may be more intelligent than we realise, despite not passing the mirror test
BELOW: The mirror self-recognition test was based on an experiment with chimpanzees