In the last lecture we talked about dogs potentially understanding the communicative intentions of humans. When we cooperate and communicate and we try to help them find things using gestures or looking in the direction where things are hidden dogs seem to be able to use that information. They almost use us like tools. That got me really excited because that was something that we thought was really important, or we still think is really important for understanding human development, and something we did not see in our close relatives, bonobos and chimpanzees. So, there was this remarkable skill that might help explain why dogs are so special in terms of how they interact with us, and I couldn't help but wonder where it came from. What's the origin of those skills? And together with my colleagues and also independently other researchers started to ask the same question. How is it that dogs can be so remarkable in using human gestures to potentially understand what's going on in terms of communicative intentions in others? So, for this lecture, The Genius of Dogs, I think chapter three, again, will be the most useful for you, and, again, playing the communication games, where you can play the gesture game with your dog, or point with your foot, and see how your dog compares to every other dog. I think that'll be the most fun as a laboratory exercise relevant to what we're going to talk about next. So when we saw that dogs were doing something that seemed flexible in their use of human gestures, we started to of course wonder about the origin of this phenomenon. Anytime you have a phenomenon in the world, the job of a scientist is to make sure that phenomenon is really real. Can it replicate? Will other people see the same phenomenon? Once that phenomenon has been established though, then the fun starts of trying to explain it. Why is it there, what is it, and what's its origin? And that's what, of course, we got excited about, thinking about dogs using human gestures. And the most obvious explanation for this was, again, that dogs are just exposed over thousands and thousands of hours to humans playing all sorts of games and trying to find food using human information. So surely what it is is that dogs are just really experienced, and have really been immersed with humans, and have learned slowly how to use these gestures. And it's true, in all the previous studies that have been done when we asked or thought that this was the probable explanation, had looked at adult dogs. Only adult dogs have been looked at and of course those dogs all were owned by people, and were people's pets. So it seemed pretty consistent, even though we were seeing a lot of flexibility, that flexibility had been learned over time. So one of the neat ways to test that hypothesis is to look at of course at puppies. So that's exactly what we did. We went and played the gesture games and we did the same game where we hide food in one of two places and then we gestured or looked to where the food was hidden. And we used puppies that were anywhere between the age of nine and 24 weeks old, and we had some puppies that were adopted by humans and were in obedience classes, and then we had other puppies that were litter reared. They were together with their litter still, and they were awaiting adoption into a human family. So they had a lot less human experience. They didn't have none. They didn't have no human experience, but they had a lot less human experience than, of course, the dogs that were already in obedience and socialization classes and that's then how we could look at the effect of exposure. Because as dogs get older, if it really was exposure, the nine-week-old dog would not be as good as the 24-week-old dogs, and of course the puppies adopted by humans would be much more skillful at using gestures than the litter reared puppies who were still waiting to end up in a human family. But the big surprise was, and it really was that we thought that was probably going to be the explanation, that was not the explanation. It is not that, or at least that explanation was not supported. We found that even nine week old puppies can use human gestures quite effectively, and that litter reared or not didn't really matter. These puppies were just really skillful at using pointing gestures in particular, and subsequent research by other groups have found that puppies as young as six weeks old are good at using human gestures, and can even use the marker, that novel marker that we had talked about earlier, to find food. So that is amazing, that something turns out to be really flexible in adult dogs is already present in a basic form in young dog puppies, and it doesn't seem that a lot of exposure explains the existence of that phenomenon. So, that then led us to think about another hypothesis which was, if it's not the exposure hypothesis, well, maybe it's the ancestry hypothesis. I mean, dogs are related to wolves, and wolves have to solve all sorts of complicated problems as social species. Maybe this is a ability that was inherited. So this is, instead of the first exposure hypothesis, is an ontogenetic hypothesis, if we're thinking about Tinbergen's four levels, this is a phylogenetic hypothesis. We're thinking about the sort of genealogy of the different species. And maybe it's just inherited, just like we inherit our abilities from our parents in some cases, maybe dogs just inherited this ability from their close relative, the wolf, that we know that dogs evolved from. So we set about trying to test this hypothesis. And of course, the rationale is that wolves hunt cooperatively, and surely they have to be able to tend the social information of other wolves, and potentially even the prey that they're hunting. And if they could realize where their other pack members were looking, maybe they would be able to go the direction that would make them more likely to be successful in their hunting. So that was what we were thinking, and we published a paper in 1999 saying that we really thought that this was probably what was going on, if it wasn't a lot of exposure necessary for dogs to show this skill.
