Short Wave - Does Your Dog Love You? Science Has Some Answers

Episode Date: August 10, 2021

(Encore episode) Clive Wynne, founding director of the Canine Science Collaboratory at Arizona State University, draws on studies from his lab and others around the world to explain what biology, neuroscience, and genetics reveal about dogs and love. He's the author of Dog Is Love: Why and How Your Dog Loves You.Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at [e-mail]. See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Maddie Safai here. Fun fact about our guest today, Clive Wynn, he has a little black, labby-looking mutt named Zephos. Fun fact about me, I have a border collie-looking mutt named Ellie. Clive, you'll like this. She was named by, when I was doing my PhD, she was named by my immunology department.

So her full name is Eliza as for, like, enzyme-linked immunosorbid's assay. Oh, that's great. Well, you know, Zephos's full name is Xenophon in honor of the ancient Greek who wrote the first book on dogs in 200 BC. Do you think they appreciate how clever we are? No, no, no. You know, that's part of the beauty. They just want you to acknowledge their love.

Clive directs the K-9 Science Collaboratory at Arizona State University. And in a new book, he rounds up studies from his lab and others around the world to argue that dogs really do love us, which, yeah, is a pretty strong word. from a scientific perspective. And certainly I've been critical of other animal behavior scientists for the sin of anthropomorphism, for ascribing to animals' human qualities. But the evidence is quite overwhelming that there is something truly, deeply remarkable about dog's capacity to form strong emotional connections to members of other species.

This episode, Clive Wynn, on what neuroscience, biology, and genetics tell us about dogs. and love. So Clive's book is called Dog is Love, why and how your dog loves you. It contains a bunch of different doggo research and takeaways. Clive and I discussed a few of those, starting with the work of a scientist named Gregory Burns, who managed to study dogs in a way that few people had before, inside an MRI machine. So Gregory Burns' work is quite path-breaking in this direction. And the brilliance lies in being able to train dogs to lie still in the scanner. Only humans had ever had their brain scanned in a scanner while they were awake. It's one thing to anesthetize an animal and place it in a scanner.

But, of course, then you're not seeing the natural brain activity that occurs when an individual's awake. No, the trick is to train an individual animal to lie perfectly still, which, of course, you know, anybody who's been in an MRI scanner knows it's quite a challenging environment. It's very loud. It's somewhat claustrophobic. Right. I've never been in an MRI machine and be like, you know who would love this? My dog. Well, right, exactly. So it was quite genius to be able to train the dogs to do this. And having got them to lie still to show them signals that indicate that different things are coming along, that different things are imminent.

And first, they just showed them signals that indicated you're going to get a piece of hot dog. You're not going to get a piece of hot dog. Right. And they then train the dogs. another signal means that your beloved human is just around the corner and is about to appear. What's so interesting there is that the reward center of a dog's brain lights up to both of those signals. And in most cases, not all cases, in most cases, the center lights up more intensely when the dog is given a signal that means your human is just around the corner, than when the dog is given a signal that means a piece of hot dog is just on its way to you.

But what was so interesting was after Gregory Burns and his team had done all this work in the MRI scanner, they then took the same dogs out and placed them in a very simple scenario where the dogs were given a choice between their human being sitting on a chair and a bowl of food placed about 10 feet away. I feel like I know what decision my dog would make. But keep on. Oh, really? I don't know. Oh, oh, you've got to try this. You've got to try this, maybe when you get home. It's not the least bit difficult to set up.

And what they found was just as for most of the dogs, their brain reward centers lit up more intensely for the person than for the food. So those same dogs chose their person more often than they chose the food. And there was a very strong relationship between how their brains have been activated by these two different rewards and what choice they actually made when they were let out of the scanner and just given a free choice to go where they wanted to go. So basically their behavior mirrored what they were seeing in the MRI. machine. Exactly. Okay, so on top of the MRI stuff, you also talked about some brain chemistry studies that came out of a group in Japan. Right. Led by Takefumi Kikusui. They discovered something kind of cool happens when humans and dogs look into each other's eyes. Tell me about that. So this is research from a group in one of the suburbs of Tokyo, and they have equipment so that they can measure levels of hormones in dogs and people. people's bodies. And in this case, what's interesting is we're talking about a hormone oxytocin, which has the nickname the love hormone. Now, no hormone is exactly the same as a

psychological state, but there's enough commonality between how a hormone responds and people's psychological experience that it's not entirely unreasonable to call oxytocin and love hormone. Certainly, we know that when people who have a very strong loving bond look into each other's eyes, levels of this hormone spike in their bodies. So you see this with mothers with their infants, newly enamored couples, not old married couples, but newly enamored couples. You see this spiking in both partners when they look into each other's eyes. And so what this group were able to do was they brought people and their dogs into their lab. And from video analysis, they looked at how much they looked into each other's eyes. And they found that in both partners, both the dog and the person,

when they looked lovingly into each other's eyes, their levels of oxytocin spiked so that you see the exact same hormonal response in people with their beloved dogs as you see when people who have a strong loving relationship look into each other's eyes. So it's another line of evidence that this love that dogs have for us and indeed we have for them is coded into our very biology. So whether or not the word love is appropriate, which I think you believe it is, it's a very similar. thing to what we see in humans that are, quote, in love potential. Right, absolutely. So it comes through between the two species, dog and human, the same way that the signal comes through when we look at people loving each other. Okay, so let's talk a little bit about genetics. You were working with a geneticist trying to find genes that were specific to dogs that might explain some of this behavior that you had seen. You were comparing dog genes to wolf genes. And you came across this

kind of interesting group of genes. Tell me about that. So there really isn't very much genetic difference between wolves and dogs. And yet, behaviorally, they're quite different animals. And we were looking at trying to pin down what was the nature of that difference. And then, it's a few years ago now, a young geneticist at the time, a graduate student at UCLA, Bridget von Holt, published a paper where she went all the way through the genome of the dog and compared it to the genome of the wolf looking for where were the changes? Where was the evidence of recent selection of genetic changes due to domestication? And in her publication, she pointed out that there was some evidence in a region of the wolf and dog genome, which in humans is associated with a very

rare syndrome called Williams-Burin syndrome. I'm just going to call it William's syndrome. Okay. William's syndrome affects 28 genes. So people with William's syndrome, they have heart deficits and circulatory deficits. But the really intriguing thing to me is that they are described in the medical literature as showing exceptional gregariousness. Exceptional gregariousness. Like happiness and interacting with other people. Exactly, Maddie. So they're described as being completely open to making friends with anybody of really having almost no concept.

of stranger at all. So this sparked my curiosity. And together with my past student collaborator, Monique Udell, we got together with Bridget von Holt and we decided to actually get some DNA from some dogs, get some DNA from some wolves, carry out our behavioral tests of sociability, of friendliness on these dogs and on these wolves and focus in on the 28 genes that are responsible for William's syndrome in humans to see if we could find a genetic signature of dogs exaggerated gregariousness, dogs desire to form friendly relationships with other individuals. Yeah. Okay. And what did you find? Well, and we found,

we identified three genes. Three genes came out and two of these three genes were already known to be responsible for the sociability component of William's syndrome. So we totally found the signal for dogs friendliness, gregariousness, lovability in their genetic code at the deepest level of biological analysis. Super interesting. Super interesting. Okay. So yeah, I think you go ahead. I totally agree. Maybe it's always the work that you've been involved in yourself that always seems the most exciting. But knowing that I, for me, it's made a big difference in how I look. Look at Zephos, you know, I used to take the view, which I blame my mother for, that our dog's apparent love for us was just cupboard love.

You know, we feed them so they act like they love us. And so I was always, and I'm a skeptic by nature, so I was always sort of looking at my dog's apparent affection for me rather skeptically. And it's just changed my heart, if you will, to accept her love as sincere. You know, if I feel better about her to think that she really means this. In her simple way, she really loves me. You know, Clive, I'm going to be honest with you, for my dog, really depends on the day, you know?

I wish I could say she greets me with joy every day, but it seems like sometimes she just looks at me and she's like, oh, you're here. Get my frisbee and we'll talk about me getting up. Thanks to Clive Wynn. His book is called Dog Is Love, Why and How Your Dog Loves You. This episode was produced by Brent Bachman and edited by Viet Le. Oh, and don't forget, if you're enjoying,

the podcast, please rate and review us in your podcast app of choice. That helps new people find us. I'm Maddie Safaya, and thanks for listening to Shortwave from NPR. NPR's Planet Money Summer School is now in session. Everything you want to know about investing from expert guest professors. New classes every Wednesday to Labor Day in the Planet Money podcast feed.