More than one billion pets live in homes around the world, sleeping on dog beds, clawing at cat trees, swimming in bowls, crawling around in aquariums. Canada, the United States, Brazil, the EU, and China make up half of those households, with half of the world’s population owning a pet of some sort. Yet despite the ubiquitous animals that lick our faces and steal food off the counter, we really don’t know a lot about the scientific side of their existence: why do dogs spin around when excited, do our cats really love us, do lizards make good pets, can single-celled organisms be considered pets (you can cut the hydra in two and have two pets!), what are parrots thinking, and can a horse be considered a pet? Or pigs (even those sent to market)? Or praying mantises? Or how about robot pets in Japan, caring for the elderly?
In this interview, I speak to veteran science broadcaster and journalist Jay Ingram, author of twenty popular science titles, including the bestselling Science of Why series. In hiss latest book The Science of Pets, he researched the latest science behind our beloved furry, and not-so-furry, creatures that sleep on our sofas and eat our pizza crusts. Along the way, he discusses the myths and misconceptions about our companions: do dogs always do their business facing north? Why are we seeing a rise in exotic pets such as tigers and bears? Are the deer and foxes we see “rescued” on Instagram considered pets and could they be domesticated? Did dogs entirely evolve from wolves, and why? Can you communicate with a turtle? Do highly intelligent octopi make good pets? And why are baby animals, like baby humans, so darned cute: have they evolved to be born cute as a survival mechanism, and would that cuteness matter to others of their own kind who might consider them their next lunch?
Q: How has the pet-human contract evolved in our civilisation?
[Jay Ingram]: Well, the history of our interactions with animals has always fascinated me, because even if you’re primarily interested in human evolution—both biological and cultural—you can’t really separate it from our relationship with animals. At least 60,000 to 70,000 years ago, there’s evidence that both modern humans and Neanderthals were creating art objects and cave paintings of animals. The Neanderthals, for instance, were using eagle feathers and various animal parts in ways that suggest symbolic or aesthetic behaviour.
Throughout that long history, there have been, broadly speaking, two main threads. One is the “pet” thread, which relates to the domestication of animals—though that came much later, more like 5,000 to 10,000 years ago. The other thread is the use of animals as displays of wealth and power. Assyrian kings, for example, would conquer foreign lands, bring back hundreds of animals, and then stage controlled-hunts where the king would kill them—all under safe, orchestrated conditions. The Egyptians were deeply fascinated by animals, the Romans by the spectacle of slaughtering them in public displays, and from there you can trace a line through to the development of menageries and eventually modern zoos.
As for the origin of true pets—the kind that aren’t working animals—the cause, if you can call it that, was probably companionship. A true pet’s value lies entirely in its relationship with us, and vice versa. The first fossil evidence of that bond goes back around 30,000 to 40,000 years: dogs buried with humans, including one remarkable case of a dog that had survived two bouts of canine distemper, presumably because its human companion cared for it. So, the real question isn’t just when that began, but how it worked—how that bond first took hold. I could go on, if you want.
Q: Is that therefore the link into the neuroscience part?
[Jay Ingram]: It is murky, because dogs probably started out as working animals of a sort. If you go right back to their beginnings, they were wolves—unfortunately, a wolf species that’s now extinct. That means any interesting genetic work we might have done on the fossils of that species isn’t possible. When we find fossil wolf remains, we can’t tell whether they belong to the specific lineage that led to dogs or just a related one.
Anyway, there are two main theories, and I’ll just sketch them out quickly. One is that packs of wolves introduced themselves to bands of humans—this was before agriculture—and the question then is: why would they do that? The other theory is that humans were the instigators, capturing wolf pups and raising them among their own. When you look back that far, it’s almost impossible to decide between the two.
There is some relatively recent evidence—by “recent,” I mean a few hundred years ago—when explorers first came to Canada and observed Indigenous peoples. They noted that people would sometimes go out, scoop up wolf pups, play with them, and then return them to the den. So it’s not at all inconceivable that much earlier humans might have done the same.
But again, even if you bring the pups in, do they become socialized to humans enough not to attack? After all, a wild wolf will do that. And that’s where I think some of the most interesting research is happening now.
Q: …What about the link between pets and surges in oxytocin and ‘happy’ hormones?
[Jay Ingram]: You’re absolutely right about oxytocin. For a while, most of the research focused on dogs. I have a dog—when you gaze into your dog’s eyes (well, my dog doesn’t seem to care much), your oxytocin level—the so-called “love hormone”—rises, and the same thing happens in your dog. It’s a powerful pair bond.
More recently, though, researchers have found the same effect with cats. If your cat is willing to look you in the eye, their oxytocin level rises just as yours does. That’s a strong connection.
But when you start looking for research that goes beyond this momentary rise in oxytocin—something that shows broader or lasting benefits—the picture becomes less clear. There is some decent evidence that dog owners, because they walk their dogs, tend to have slightly healthier hearts than people without dogs. But when it comes to claims like “pets alleviate depression,” there’s really no solid evidence. In fact, the findings so far are pretty ambiguous.
And—I don’t really want to tell you this—but in one study that found no significant overall effect, cat owners were actually more depressed than the control group. I’ll leave that one to you to explain.
Q: Is it fair to say that pets reveal more about us than we’d care to admit?
[Jay Ingram]: looking ahead—and gauging the incredible rise not only in the money spent on pets but also in the sheer number of pets around the world—it does make you wonder what 2050 is going to look like in terms of pet ownership.
You mentioned neuroscience, and I agree—it’s very tricky. We can record all kinds of brain activity from humans because they’ll willingly sit in an MRI scanner and so on. But really, the big question is: what’s going on in the animal’s brain?
There are, of course, many different kinds of pets, but it’s safest to talk about dogs and cats, because that’s where most of the science has been done. It’s still very early days in terms of understanding what a dog or cat’s mind actually is. What we do know—mostly from studies on dogs—is that the presence of a familiar person is calming for them. They show that through their behaviour: how they wag their tails, whether they wag them, and even which direction they wag them in.
I think we’re right on the cusp of being able to do real brain research with animals, and maybe AI will help interpret whatever data we gather.
But the truth is, any book about pets is really a book about humans. It’s not about the pets themselves. I’m always amused when friends send me pictures of their dog or cat, because I’m tempted to write back and say, “If you’re not in the picture, it’s a misrepresentation of what’s going on.”
As for how two-way that relationship really is—I think there’s plenty of evidence from pet owners that pets do respond strongly to their humans, while maintaining, in the case of cats especially, a certain amount of independence. That probably traces back to how they were first socialized and became pets. Cats always had a function; dogs had to be trained to have one. Cats came pre-equipped with a useful role—killing rodents—and that’s been valuable for millennia.
Q: What are your views on the ethics of pet ownership?
[Jay Ingram]: … when I was writing this book, I went off on a tangent about trophy hunting and became completely absorbed by it. The late, great biologist E.O. Wilson sometimes compared biologists like himself to hunters—in the sense that they move through the environment completely aware of everything around them. They empathize, to an extent. And I thought, well, okay, I can understand that, because we know of many Indigenous groups who see hunting as an integral part of their life and spirituality.
But trophy hunting? That’s different. I don’t know if you’ve read much about it—and you really don’t need to—but the language they use is fascinating. They talk about an “ethical hunt,” or say, “Oh, the beast was magnificent,” or “I’m so proud.” All of that, to me, is camouflage for the underlying truth: I wanted to kill a giant animal and be photographed beside it.
So I started thinking about biophilia—our supposed love of life—and how, in this case, it’s being exploited. These hunters justify their egos by praising the animal, because they know people naturally empathize with animals.
When it comes to ethics—and if you’re asking about the ethics of pet ownership—it’s becoming increasingly clear that we don’t yet know how simple an organism can be and still be conscious. There’s now quite good evidence that bees not only learn tasks but can watch another bee perform one and then learn it themselves. Twenty or twenty-five years ago, no one would have believed that possible.
So if we’re willing to accept that even insects might be conscious at some level, that raises uncomfortable questions. As I mentioned in the book, I used to keep a pair of lizards in an aquarium and fed them live crickets. At the time, I didn’t think twice about it—I didn’t believe crickets had any inner life at all. But now I wonder if I was actually creating the worst moments of their existence by feeding them to my lizards.
Consciousness itself, as you know, is an incredibly tricky subject. We still don’t understand how it happens. So attributing consciousness to insects is a generous step—but one that really needs more evidence.
The ethical questions around pets, though, go beyond what their brains can do. It’s also about whether we should keep them at all. There are so many issues. When I was writing about parrots, for instance, I looked through the full list of parrot species worldwide to see how many were thriving and how many were endangered. Roughly three-quarters to seven-eighths of them are not doing well. And when you buy a parrot, there’s often no way to know where it came from—it might have been captured in the wild.
Then there’s the problem of people getting a bunny for Christmas and losing interest two months later. We’re the only species on Earth that keeps pets, and that alone suggests there must be a good reason for it. It’s hard to even imagine a world without pets. But we do need to be aware of all these issues—from abandoning animals to breeding them to extremes simply because they look “cool” or different. Thankfully, that last trend seems to be slowing down.
Still, there are ethical concerns everywhere you look.
Q: …how do we then extrapolate that to look at the moral philosophy of pet ownership?
[Jay Ingram]: …it really depends on the culture, right? There are still countries in the East where people eat dogs without compunction and see nothing wrong with it. And you’re right—I mean, I had a steak a couple of nights ago, so that’s actually pretty bad when you think about it.
But what’s fascinating is the pushback, especially in the U.S., against lab-grown meat. The big meat producers are lobbying hard and, in some places, actually making it illegal. There’s so much happening in the U.S. that boggles the mind, but that, to me, is just ridiculous.
I put it another way in the book—mostly playfully—and said: well, what if your cat, instead of being eaten by a wolf, was run over by a car? Would you eat it?
There have been some really interesting studies on that, particularly by Jonathan Haidt. He compared people’s reactions to that scenario in Brazil and the U.S. And what he found—and I found this fascinating—was that people at higher socioeconomic levels were actually okay with the idea of eating their pet. The reasoning went: they didn’t kill it, it was an accident, nobody was hurt. If it’s going to be cremated anyway, why not make it a barbecue instead?
… just to hearken back to what we were talking about a moment ago—about attitudes toward animals—one of my favourite animal writers, Harold Herzog in the U.S., used to study roosters that participated in cockfights. He pointed out that if you compare a rooster raised to fight—and then probably die a horrible death, slashed to pieces—with a broiler chicken whose entire life is spent confined to an 8.5-by-11-inch space, you have to admit that the rooster raised for fighting actually has the better life. It might live five years before it dies, but during that time it eats well and gets to run around.
And I think, in saying that, he really got at something important: our reactions to these issues are often pretty superficial. We’d be better off doing a little deeper thinking about our attitudes.
After all, there’s no universal rule that says you shouldn’t eat dogs. Different countries, different cultures—different norms. When people study pet ownership in societies that are still largely hunter-gatherer, there’s often this idea that a den of puppies might be collected along with an adult. The puppies are raised with the group, and one might be chosen as a pet while the others are eaten. So in some cultures, it’s not one view or the other—it’s a mix of both.
I think we have to remind ourselves that the cultural rules we live by don’t necessarily apply as broadly as we’d like to think.
Q: …what if we end up with AI pets!?
[Jay Ingram]: It’s so interesting you asked me that question, because I participate in a podcast called Defy Dementia, where we explore ways people can lower their risk of developing dementia. The topic we’re about to tackle is dogs—or pets in general—as companions for people living with dementia.
There isn’t a lot of hard data on this. There’s some reasonably good evidence for live animals, but they’re messy, hard to care for, and unpredictable. So the question becomes: how often do you introduce them to someone living with dementia, and at what stage of cognitive decline?
Robot pets, on the other hand, seem to have had some success in calming and amusing dementia patients. But not everyone likes that idea. The philosopher Robert Sparrow in Australia, for instance, argues that either you’re deceiving the patient—making them believe the robot is alive—or you’re encouraging them to deceive themselves. And either way, he says, that’s not moral.
Others who’ve worked extensively with robots are disappointed for a different reason. They feel uneasy about this growing acceptance that spending time with a robot is fine—and if it makes you happy, then that’s enough. But are you actually having a conversation? Of course not. You wouldn’t really call it a conversation with a pet either, but you know what I mean—it’s not real, and it never will be.
My artist friends tell me the same thing: they insist that one will always be able to tell when a piece of art was created by a human. And I say, I’m not so sure about that. The way things are moving, I wouldn’t guarantee it. In fact, I was just talking to my publisher two days ago, and she said they’ve already received entire manuscripts written by ChatGPT.
That’s the thing—we’re on this strange cusp right now. The naysayers say, “Look at this garbage ChatGPT produces,” while others counter, “Yes, but what about the ones you didn’t realize were written by it?”
People form emotional attachments to robots too. That’s been especially true in the military—there are stories of mine-detecting robots being blown up, and soldiers rushing out to rescue them. So I don’t see why that same kind of bond couldn’t develop with companion robots—not just for people with dementia, but more broadly.
I’m sure it’s coming. And Robert Sparrow, the philosopher I mentioned earlier, is already worried about what happens when it becomes cheaper to have a robot than a human caregiver—because at that point, fewer dementia patients may have any human contact at all.