No two humans process the death of a loved one the same. What about other animals? For instance, in the case of chimpanzees, what we see is that there is huge variability in how they react to death. It's Thursday, October 24th, and you're listening to Science Friday. I'm Sci-Fi producer Shishana Bucksbaum. Throughout human history, humans have given a lot of thought to death. We grapple with the inevitability of mortality, we create elaborate burial rituals,
and we decide how best to mourn the loss of a loved one. But what about other animals? How do they understand death? Here's Sci-Fi producer Kathleen Davis in conversation with Dr. Susannamonso, author of Playing Possum, How Animals Understand Death, an associate professor of philosophy at the National Distance Education University in Madrid, Spain. Dr. Monso, welcome to Science Friday. Thank you so much for having me. It's a pleasure to be here.
So I want to jump right in and talk about the animal that's in the title of your book, which is a possum, or as they're sometimes called, opossums. What's so special about possums and their relationship with death? Yeah, so the opossum is an animal that I find really fascinating, apart from the fact that they're super cute, in my opinion. The opossum, when she feels threatened and she feels like she cannot escape, she pretends that she's dead. But she does this in an
extremely elaborate way. So she adopts the bodily and facial expression of a corpse, her body temperature drops, her breathing and heart rate are reduced. She expels this putrid smelling liquid from her glands and she stops responding to the world. She also opens her mouth and her tongue hangs out and it adopts this like blue issue. So it's a very, very elaborate ritual. If you don't know ahead of time that she engages in this little trick, you would be fooled by her for sure.
And the opossum is in the title of my book because I think the opossum gives us some clues for how animals understand death. And this is not because the opossum herself understands that she's playing dead. I think that for the opossum, this is probably an automatic reaction, like when our pupils dilate or her hair stands on end when we're afraid. Her display tells us something about how the predators that she's trying to deceive understand death. So in order to understand this,
I think it's helpful to think about the peacock's tail. So the peacock has this beautiful, gorgeous, enormous tail that is like very problematic to have in a lot of regards because it makes it more difficult to fly and to run away from predators. However, they have this tail because the pea hands love it. And so the tail tells us something about the pea hands mind. It tells us
what she finds sexy. And something similar can be said of the opossum's death display. It's not that it's telling us something about the opossum's mind, but rather it's telling us something about how her predators understand death. It shows us that they think of dead individuals as having a certain facial expression and bodily posture as being cold as showing no signs of breathing, smelling bad, not responding to the world, et cetera. So the opossum's display gives us a window into the minds
of her predators. It shows us how they understand death. So in your book, you write a lot about this thing called the minimal concept of death. Tell me a little bit about what you mean by that and why it's important to define when we're talking about animals understanding of death. The question of whether animals understand death is one that requires us to first define what exactly we mean by understanding death. And more often than
not this notion, the concept of death has been understood in very demanding ways. The question has been construed as do animals have a concept of death that is equivalent to the human adults average concept of death. So one that entails an understanding of the concept of absence of infinity of abstract thinking. I think that understanding this question this way on the one hand is a little bit unfair because that's not usually how we pose the question when we think about
human children. Like human children don't acquire a concept of death overnight. Rather, it's something that takes them a while to develop. It takes them several years before they fully understand death. Like if you've ever played Super Mario Brothers with a six-year-old, you will know that they do grasp something about death, right? So we're kind of setting a double standard if we're if we're asking the question in different terms when thinking about children and thinking about
animals. But also I think that construing the question this way just makes it a not not very interesting question. You know, if what we mean when we ask if animals can understand death is whether they have anything equivalent to the human adult average concept of death, the answer is going to be no. And you know, that would have made for a very short book. So it's more interesting I think to ask do animals have anything that counts as a concept of death? And for that, what I do
is I begin from what I call the minimal concept of death. So like the bare minimum that an animal would need to understand in order to be credited with some understanding of death. And the minimal concept of death basically just amounts to the idea that dead individuals don't do the sorts of things that live in beings too and that this is an irreversible state. So that once you're in the state, you cannot go back to life. And so the idea is we start from there and then we can look into
how complex animal's concept of death actually is. Okay, so let's start with some of the smallest examples of creatures in your book. I was really fascinated to read about ants. So ants will try to save a fellow ant who is trapped and they'll remove dead ants from their nests. But you also say that they don't actually seem to understand death. So explain to me what this means. In the case of ants exemplifies what I call stereotypical reactions to death. So these are reactions to
death that are kind of pre-programmed, so to speak. So the animal doesn't need to learn them or acquire them, but rather evolution has sort of programmed them into the animal's behavioral repertoire. So these reactions are triggered whenever the animal senses certain stimuli in her environment. So for instance, when it comes to ants taking out of the nest, their dead nest mates, this is something that presupposes their capacity to tell live ants apart from dead ones.
But we know that there's no concept of death involved because this behavior of theirs is very dependent on the presence of certain cues in the environment, such as certain chemical elements given off by decomposing corpses. An example of this is oleic acid. So if you take some oleic acid and you put it on a piece of leaf or a little pebble or even a live ant, the ants are going to treat it like a dead ant and they're going to pick it up and take it out of the colony. So this shows
that they're not really understanding what being dead means. They're just reacting in a way that they can't really help to certain cues in their environment. So let's pivot to talk about our closest relatives, which are primates. What do we know about their understanding of death? So I have to say that the research here is still very young and we're still only just starting to ask these questions. So we don't have any real certainty here about how
exactly they understand death. However, we do have certain important pieces of evidence. For instance, in the case of chimpanzees, what we see is that there is huge variability in how they react to death. So for instance, there was a very famous case that came out about 10 years ago where an adolescent male had died and the scientist documented the reactions of the remaining group members to the
corpse of this individual. And what they found was huge variability in the reactions. So some of them sat around the corpse and looked at it or inspected it in different ways by touching it or sniffing it, others reacted aggressively, hitting the corpse or engaging in dominance displays. And there was also one female who stayed behind once the rest of the group had left and started to clean the teeth
of the corpse. So this doesn't tell us necessarily that they understand death, but it does tell us that it's something very different from the case of the ants because what we're seeing here is what I call cognitive reactions to death. So these are reactions that involve the psychology of the individual, her emotions, her personality, her life history, her beliefs, her desires, and so on.
And that's why we can't predict in advance how they're going to react. Apart from that, we see in a lot of primates, we see a lot of interest towards corpses, we see a lot of what looks like grief. So a lot of clues that suggest that they may have an understanding of death. So since chimps are so closely related to us, could they be having similar responses to death
as we do, as humans do? So in the literature, very often, scientists have argued that what we see in chimpanzees are behavioral reactions that are analogous to a lot of the human behavioral reactions to death. However, I think this is a little bit of a dangerous road to go down. We have to be wary of what I call emotional anthropocetism, so the idea that the only emotional reactions to death that are worthy of our attention are human-like reactions.
Because some of the reactions to death that we see in other animals are very difficult to make sense of from a human perspective, at least from the perspective of Western contemporary societies. So we often see reactions like cannibalism or necrophilia that would be very problematic to see in our societies. And so this may lead us to somehow conclude from that that they don't
understand death because they don't respect corpses the way that we do. But that for me, it doesn't really follow, because there's one question which is, can you understand what death means? Can you understand the finality of it? Can you understand that individuals cannot come back to life? And a different question is, do you react to death the way a human would react? For instance, do you react with grief? Grief for us is like the paradigmatic emotional reaction to death.
But it doesn't necessarily follow from understanding that someone has died, that you're going to grieve them, right? So for instance, when Amy Winehouse died, I could understand that she wouldn't be producing any more music. But I didn't necessarily grieve her, even though of course I was sad, as an Amy Winehouse fan, I was sad that she died. But I didn't grieve her because I didn't have the sorts of emotional bond that you need to have towards an individual in order to really
be said to grieve their loss. Right. I have certainly seen videos on the internet for example, or have heard stories where people definitely put that emotion of grief onto animals, whether it's deserved or not, right? Like, for example, I've certainly seen videos of elephants that seem to be having like a deeply emotional response to a dead elephant in their group, or there are people who will have two pets who grow up together and then one of them dies.
And then the other one seems to be really melancholy and actually be quite sad. But is there any sort of scientific proof that these animals are experiencing grief? I mean, the word proof is a very strong word and it's very rare that in science we get proof of things. But it's certainly a well-supported hypothesis. We do have a lot of evidence that animals grieve. Anthropology is Barbara King for instance wrote this beautiful book called
How Animals Grieve that has a lot of stories of animals grieving. And I think it's super important topic and it's definitely something that we need to pay attention to, especially because it has very important ethical implications. If animals do grieve, it has implications for, you know, our treatment of them. However, the problem is that if we're only focusing on grief, then we're potentially missing out on many other dimensions of animals' relationship with mortality.
You know, a very important dimension for instance is the one of violence. Very often death in the natural world is something that animals cause on purpose, you know. And very often death for animals is not a loss but a gain. And you know, if we're only talking about grief, then we're only talking about context where death is a loss, which you know, is going to be something that happens very often and it's a very important question, but it's not the full picture because very often
death is going to be a gain. So for a long time, scientists and philosophers didn't think that animals could possibly understand death or conversely that it wasn't worth studying. So what has changed? Well, I still think that a lot of philosophers think that and a lot of scientists think that, so I'm not so sure that that much has changed, but it's certainly starting to garner attention. I think one of the reasons why scientists are starting to ask this question has to do with
the cognitiveist revolution. So this is something that started to happen in psychology in the 80s, where there was this reaction against behaviorism. You know, this dogma that we shouldn't be discussing the minds of animals and we should just be describing their behavior. So once, you know, scientists got rid of behaviorism or they left it behind, they started to ask questions about the minds of animals and they started to ask questions about the capacities that animals have.
But still, there's a lot of fear of falling into anthropomorphism and attributing human-like qualities to animals in an unwarranted way. But at the same time, the evidence has just started accumulating. And there have been more and more cases that biologists in the field have just happened to stumble upon. And at a certain point, the number of cases became so big that, they could no longer ignore it. And so this new discipline, comparative thenotology, was born
about, you know, a decade ago. And it's starting to gain a lot of traction as more and more people have started sharing the data that they've gathered. Well, there is clearly so much to talk about here, but unfortunately we've run out of time. But I'd love to thank my guest, Dr. Susana Munso, author of Playing Possum, How Animals Understand Death. Dr. Munso, thank you so much for taking
the time to be with us today. Thank you. One last thing before we go, did you know that Science Friday has a book club every month we choose a fascinating science book, including classics and new releases to read together. Next month's book is A Sand County Almanac by Aldo Leopold, a collection of essays from the 1930s and 40s about wildlife, natural history,
and Leopold's now infamous concept of land ethics. Consider joining our online community of book lovers and science nerds at science Friday dot com slash book club. That's it for today. Lots of folks helped make the show happen, including Sandy Roberts, Robin Casmer, Jordan Smudjick, Charles Bergquist. Tomorrow, a roundup of the top science news of the week. Catch you next time. I'm sci-fi producer Shoshana Bucksbaum.