This is another post that I am mostly writing from memory. Basically because it is a topic that fascinates me, I’ve read a ton about it, and most people are profoundly under informed. We’ll start with talking chimpanzees and gorillas. A lot of people are under the impression that these animals have learned to communicate with sign language or by pointing at symbols. Koko the gorilla and Kanzi the chimpanzee are the most well known. And one can easily find all sorts of credulous and basically scientifically illiterate videos and articles about them online.
Unfortunately, the actual science on talking apes is quite clear. While apes and other animals can learn the meaning of hundreds or thousands of words and use them in a variety of contexts, they can’t talk. And by talking, I mean stringing words together into meaningful sentences. Chimp babies and human babies mature pretty much the same way up until they start learning words. And shortly thereafter the human children start stringing the words together into longer and longer sentences. Chimps don’t. Or in another way of looking at it, even small children can tell the difference between “Dog bites man” and “Man bites dog.” No known animal can make that distinction.
There have also been claims of talking birds and such. Same story. Under anything resembling rigorous conditions, they simply do not exhibit comprehension of grammar. The people training these animals often strongly disagree, but operant conditioning or the Clever Hans effect explains what they are experiencing. It’s actually a little sad, sometimes the trainers and keepers of such animals desperately want to believe the animals are exhibiting language comprehension, but the science says no.
A related topic is do animals have theory of mind? Theory of mind is the idea that an organism recognises its own mental states, and recognizes that other organism also have their own perspective and mental states. Healthy humans understand this and exhibit theory of mind, but there are certainly injuries and brain conditions where it is absent.
How do scientists know if animals have theory of mind? Good question. The mirror test is one stab at it. That’s where when an animal is unconscious one puts a mark on its face in some way that is undetectable except by looking in a mirror. And if the animal looks in the mirror and then explores the mark with its hand, it is an indication that the animal understands the image in the mirror is itself. And at least has some inkling that it is aware of its own existence. Most chimps pass this test. Some gorillas, some elephants, some birds. Now we're getting somewhere! Unfortunately it has recently been discovered that some ants pass it as well. What the hell does that mean? Scientists don’t really know, animal cognition is a minefield.
Here’s another fascinating test. Show a chimp a video of someone hiding a treat in a room, and when they are let into the room, they go right to the treat. Easy enough. Show a chimp a video of someone hiding a treat out of sight in a room, but there is a witness in the room who can see where the treat is hidden. When let into the room, the chimp will try to get the witness to show them where the treat is hidden. Seems simple, the chimps can tell the witness saw where the treat is hidden.
OK then, same video, but this time the witness is blindfolded and can’t have seen where the treat was hidden. Let the chimp in the room, it still tries to get the witness to show it where the treat is. Human children can pass this test around age 3 or 4, chimps never pass it. So chimps don’t have theory of mind? Beats me, just another one of those things that says the human brain’s perception of the world is more nuanced than a chimp’s brain for some reason.
In other ways though, chimps are a big fail. They did an experiment where chimps got to select one of three overturned cups, and if they picked the right one, there was a treat under it. And then they had human experimenters point at the correct cup, they wanted to see how long it would take for the chimps to figure out they didn’t have to guess, they just had to select the cup the experimenter was pointing at. And guess what, chimps were terrible at this. It got so frustrating that one of the scientists said “dammit, my dog could do better than this.”
So, the next day (who says science isn’t fun) he brought his dog in for testing. And sure enough his dog learnt really quick to pick the cup the scientist was pointing at. Puzzled looking chimps standing around in the background wondering how the dog knew where the treat was. OK, I made that part up. So dogs are smarter than chimps? By most measures, no. In this one, yes. Just another indication of how devilishly complicated animal intelligence and cognition is.
I was going to cover the evolution of speech, but that will have to wait for another day.
(Public domain image courtesy of Snappygoat and Wikipedia.)