Before we can decide if we’re underestimating the intelligence of non-human animals, we have to consider what we mean by intelligence, because there are all sorts of different kinds. Intelligence is really a response by an animal to its own environment, and since every animal has different problems to solve, it ends up with a different kind of intelligence. To give a concrete example of that, there have been experiments in which pigeons are shown images and rewarded for pecking or not pecking each one, and they can remember hundreds of images for up to a year. I’d find that impossible to do myself, and I’m sure most people would. It’s a specialist ability that may come from their need to remember landscape as they’re flying and to use that in their navigation, so it’s a particular way that they solve problems in their environment.
One way we’ve underestimated animals is by not appreciating this richness of different kinds of intelligence. That can come from not really understanding the kind of problems an animal’s environment poses and therefore how it might have evolved to solve them. It’s hard to imagine what it’s like to be a bat, for example, and what they’re solving with echolocation
The animals we regard as intelligent, such as primates and dolphins, tend to have the ability to respond flexibly to problems because this is what we intuitively recognise as “intelligence”. Instead of always responding in the same way to the same kind of stimuli, these animals can use something they’ve learned in one context and apply it in a different one. To give a human example, if I don’t have a screwdriver I can look around for something that can function in the same way, such as a flat knife. That’s the kind of thing that humans and great apes are very good at, and it’s what researchers mean when they’re talking about intelligence.
Pigs are supposedly pretty good at this flexible learning too, but I suspect that many of the species we’ve lived with for a long period have no need for flexible intelligence. With cows and sheep, for example, you have to think of what kind of problems their ancestors would have had to solve. Grazers must escape from and be wary of predators, but they do not have to catch unpredictable prey like a carnivore, or find and process lots of different kinds of foods like an omnivore.
Because up till now we’ve concentrated research on a small number of species, it’s almost inevitable that we’ve underestimated the intelligence of many animals.
However, because up till now we’ve concentrated research on a small number of species, it’s almost inevitable that we’ve underestimated the intelligence of many animals. It’s only recently that parrots and crows have been tested with the kinds of tasks primates have been given, and there have been some extraordinary discoveries. There was a fascinating study last year showing that, though their brains are very small in comparison to most mammals, they have more than twice the number of neurons than mammals with similar size brains, so they’re packing the neurons efficiently in a small space, suggesting they have a different way of organising their brain.
We’ve also recently realised that we can’t make assumptions about how well humans would behave in the tests we use with animals if we haven’t specifically tested them. There’s a famous experiment that’s been used for some time on various species, particularly primates, to see what they understand about the effects of gravity. They’re given a hollow tube with food in it and a pocket in the middle that will trap the food if it falls into it. Once they’ve learned to poke the food from one end with a stick to get it out, the tube is rotated so that the pocket is on the top and can’t trap the food anymore. They continue to poke the food from the side of the tube that they’ve learned to use rather than understand it doesn’t matter which end. It looks like an unintelligent behaviour, and that’s the way it was always interpreted until a 2005 experiment on adult humans found that they had a tendency to do the same thing.