‘Elephants show immense interest in corpses’: Susana Monsó, the philosopher examining what animals know about death

An opossum will play dead to escape a predator. Ants remove the corpses of fallen soldiers from their nest. A group of chimpanzees will gather to bid farewell to one of their own. Like humans, animals have complicated, surprising relationships with death. Susana Monsó , associate professor of philosophy at the National University of Distance Education in Madrid, examines animal perceptions of dying in her new book, Playing Possum: How Animals Understand Death .

Most pet owners wouldn't think their dog or cat pays much mind to the great beyond. How have animals been observed to respond to death? We don't see a standard response in every species, but rather many different responses to death. We've seen many cases of mammalian mothers carrying the remains of their deceased babies – a very common phenomenon, especially among primate mothers, that might be an expression of grief. There was a very famous case of a chimpanzee seen cleaning the teeth of the corpse of an adolescent male of the group. We've seen another chimpanzee play-parenting the corpse of another species. And there are many cases of companion animals feeding on the remains of their caregivers.

Elephants have been witnessed showing immense interest in the corpses of fellow elephants. There was a very intriguing report that had found the corpses of five different elephant calves buried within tea estates in India, and some suggestions they were buried by elephants themselves. So we have a wide variety of reactions to death, and that raises the question: what is going on in their minds?

Presumably it's not the same as what's going on in our minds when we think of death? Humans are animals of very high cognitive complexity, but also we are immersed in cumulative cultures where we have all these symbolic representations of death and elaborate rituals. We have this scaffolding of cultural systems and processes that shape our perception and understanding of death, that non-linguistic animals probably don't have. So for animals, the way they learn about death is solipsistically. Each animal is on their own journey, and is dependent on their own experiences and life history to shape how they understand death.

What do these animal responses to death tell us? Two things. On the one hand, they can tell us how animals understand death on a cognitive level: do they understand that death implies the irreversible cessation of functions? But we can also see something about the emotional significance that they attach to this event. In humans, we tend to think of death as something that triggers grief and is followed by a mourning response. But throughout our lives, we hear about many people dying, and for most of them we don't grieve because they're not close to us in any way.

So these are two different things: what we can process cognitively, and how we deal with it emotionally. In animals, we see variations of both these things, and we need to have an open mind with regard to how animals might understand death, but might also react to it emotionally.

It's tempting to explain animal behaviour by pointing to our human emotions. Does that risk conflating their response to death with our own understanding? The danger of anthropomorphising animals and projecting our own human experiences and way of understanding the world on to them is a legitimate worry. But the opposite worry is also there – the idea that because animals aren't human, they can't have any human-like psychological capacities. This is a corresponding bias that Kristin Andrews [professor of philosophy at York University, Ontario, Canada] has called anthropectomy.

Even with empirical studies, a cynic might wonder whether we can ever truly know the workings of an animal's mind. Might all this be futile? I've heard that worry, but I think it's overstating that objection to say: "Well, let's just abandon the whole thing, because we can't ever fully know what's going on inside an animal's mind." We can't achieve certainty in this debate, but science doesn't move with certainty. What we have in science are hypotheses that are more or less supported by the data.

Animal perceptions of death are often studied from a psychological or biological perspective, but you're coming to it from a philosophical background. Why bring philosophy into the mix? Philosophy is a part of science whether we like it or not. Science is about gathering data, but we have to decide first what questions we're going to be asking, how we're going to be addressing these questions, what methods we're going to be using. And then, once we have the data, we have to choose a statistical method and interpret those results. These are all steps where philosophical choices are made – choices that have to do with concepts and how we're using them, what our values are, the theory that we are bringing to the table.

So the philosopher can help the scientists really reflect on how the concepts are being used, what suppositions are driving the scientific endeavour, what assumptions are in place, whether there are biases in how the questions are answered or the experiments are designed. Philosophers have this training in conceptual analysis and looking at things from a wider perspective, which I think scientists can really benefit from.

Your book ends on the hopeful idea that if we accept we're animals, we might better face our mortality. How has your outlook on death changed since studying this topic? A lot of people, when they're about to turn 30, become obsessed with death. It was definitely my case. When I began studying this topic, I didn't realise the connection at the time, but looking back, it's very obvious that I was searching for answers.

Since studying death, I've looked at it from every possible angle, I've examined it and dissected it, and it's lost a lot of its emotional weight. I think it has to do with normalising it, understanding that it's just a fact of life, and that it's not something unfair that happens to us. It's just the deal – if you want to be alive, then you have to die. Pretending it's not going to happen makes the fear of death stronger than if you look at it head on and just accept it for what it is.