Nicky Clayton: Can animals plan for the future?

In this edition of Titans of Science, Chris Smith speaks with expert in animal comparative cognition, Nicky Clayton...

Chris - When we first met, and this is quite a while ago now, you a turned up with a whole load of Robbie Burns's poems and you read them on the radio because you were referring to the fact that you'd just done a study on this whole question of planning for the future and having a sense of time. Because that, and I've quoted you on this so many times because it made such a huge impression on me when you did that study, because you were able to show these animals experience something, realise what it's telling them, and extract the right information to then know how it should inform their future behaviour. And they do it very quickly. Talk us through that study again because it's fascinating.

Nicky - Sure. So we called it the 'Planning for Breakfast Experiment'. And the history behind this is that many people assumed that only humans have what's called mental time travel. And mental time travel means the ability to travel in the mind's eye to think about the past and plan for the future. And in the Robbie Burns poem, 'To a mouse', Robbie Burns has just ploughed through a field mouse's nest. And he's feeling awful. He's riddled with guilt because he thinks that, thanks to his clumsy actions, the little mouse is not going to make it through the night and it's going to die. And then a thought comes to him and you think, oh, thank goodness for that. And he turns to the mouse and he says, 'still thou art blessed compared with me. The present only touches thee. But oh, I backward cast my eye on prospects' drear. And forwards, though I cannot see, I guess, and fear.' So from Robbie Burns' perspective, said far more eloquently than most of us could possibly dream of, he was thinking that the mouse was stuck in time, that the mouse knew about the present, but had no real notion of the past. It might learn things about the path. That's a good place to be. That's a good place to get food, but not to have an experiential memory of what happened. Nor would it be able to imagine the future and therefore the fact that its nest had been destroyed. If you're just living in the moment that has no significance. I don't need the nest right now. It's not time to use the nest to go to sleep yet. So it doesn't matter. But of course if animals do have a sense of the future, that they really can imagine the future, then that has huge implications. And what we did with the jays was to capitalise on the fact that they naturally hide food. We call it caching just from the French word 'cacher', to hide. But they naturally hide food. And we know that they have excellent memories of where they've hidden their staches or caches of food. And we wondered whether they could also use that information to plan for the future. Because if you think about it, caching by definition is orientated towards the future. The only point of hiding stuff now is if I'm going to be able to get it back in the future, otherwise it's just a pointless activity. And so in the experiment we gave them a series of compartments that they could explore during the day. And each evening they ended up going to bed in one of the two end compartments and it was randomly chosen. So for some that was the left compartment, for some it was the right compartment. But what they learned over six days was that sometimes they'd end up in the left compartment and sometimes they'd end up in the right compartment. And for half the birds when they ended up in the left compartment, when they woke up in the morning, breakfast would be served. Whereas when they ended up in the right hand compartment, when they woke up in the morning. It's like a Motel Six, no breakfast available, sorry guys, you're just going to have to go hungry. And they wouldn't get food until late morning. And for the other half it's the other way round. So it wasn't the location, it's just the idea that you have a sleeping compartment where breakfast will be served in the morning and a sleeping compartment where no breakfast is served, the hungry room if you like. And then on the evening of the sixth day, we gave them the opportunity to hide some food. So we gave them a bowl of nuts and some trays in which they could hide the food. And we found that the birds spontaneously hid the food in the hungry room, the room that doesn't serve breakfast in the morning. Because in the absence of knowing whether you'll be in the breakfast room or the hungry room, then the best thing to do if you like breakfast is to hide food in the hungry room. So you will have breakfast in the morning, bit like taking a packed lunch if you're going on a long hike somewhere.

Chris - Do you think it's just birds that are doing that or would that mouse have realised that it was in trouble because his nest was gone?

Nicky - Well, so far it's only been tested in chimpanzees and corvids. It's not been tested in any other animals. We've done a few experiments in cuttlefish and they're very interesting. They're the cousins of the octopus. And of course they're extremely intelligent, but they're not social. But we've given them various kinds of self-control kind of experiments. So you can have one marshmallow now, well a shrimp for a cuttlefish, or you can have four marshmallows later if you are a child, four shrimp if you're a cuttlefish. And the cuttlefish are able to wait. And we've also shown that if they learn that shrimp are on the menu for dinner, they eat fewer crab for lunchtime. But we've not done these actually carefully controlled future planning experiments yet. But Alex Schnell in my team, along with Elias Garcia-Pelegrin, Christelle Jozet-Alves, and I are just about to start an experiment to see whether the coconut shell carrying octopi are able to plan for tomorrow. But in terms of shelter rather than breakfast.

Chris - It would make sense, wouldn't it, if they could under certain circumstances. The other thing that's often mentioned, when we have young children, we begin to wonder when they realise who they are and what they are. And we do these experiments where we stick things on their forehead and show them their reflection in a mirror. This whole idea of a theory of mind, do your birds have that? Do they recognise themselves? Do they know who they are?

Nicky - Theory of mind refers to the ability to think about what others are thinking and to be aware that your thoughts may be different to theirs. You may know things they don't or they may know things you don't. And it always struck me that theory of mind is rather like mental time travel, except that it's about a different sense of others. So mental time travel is about having an awareness of other times. I know I'm in the present, but I can imagine what I will be doing in an hour's time and I can reminisce about what I was doing an hour before we started our conversation today. So that's all the time. And theory of mind is kind of the same thing, but it's about self rather than time. It's about understanding that other selves can think differently and that my own self can think differently at different times. And so there's a fluidity in that progression, I think. And I think probably the strongest evidence for theory of mind in corvids, and I would say in non-human animals in general, comes from an experiment that we did on the jays, again, capitalising on their ability to cache or hide food. And so what we did is we know that these birds don't only hide their own food, they also steal the food of other birds. And so what we did was we had a setup where the bird either hid food in private on its own or in the presence of another bird who could watch it, couldn't get the food physically at the time because there was a barrier in the way, a window if you like. But the nosy parker could get a good view of where everything was being stashed. And then a short time later, once the potential thief had left the scene, we gave them the opportunity to recover their caches. And when the birds are just cached in private, they recover the food and they eat it. But if others had been watching, then although they recover some of the food and eat it, they move a lot of the caches to new hiding places, which by definition, the nosy parkers that have been watching don't know about because they've now been placed in new hiding places. And specifically probably the most striking finding was it was only those birds who themselves had been thieves in the past that moved the cache to new places, <laugh>. So in short, it takes a thief to know a thief. So birds that have had experience of stealing other bird's caches might be using a form of experience, projection of putting yourself in someone else's shoes and going, 'Hmm, I bet that nosy parker over there might steal my caches. I better move them as soon as they've left to new places because that'll protect them.' Birds that haven't had the experience of having their own caches stolen before don't do it. Suggesting that it's not just a hardwired automatic response that's inborn, but it's actually because of experience. But the birds have never been rewarded or punished for doing this. The experience they've had is of stealing caches, and they're using that experience to predict what another bird might do and then take action in order to protect those caches for the future. So it's a combination of theory of mind, of thinking about what another individual might do, anticipating and predicting what they think it might do, but also integrating that with the knowledge of, I better do this if I want my caches back in the future.