Instant Genius - Why we love pets and why strangers help each other

Episode Date: November 2, 2017

When she was 19, a stranger saved Dr Abigail Marsh’s life. Because of that moment, Dr Marsh work studies the psychology of people who help total strangers. We talked to her about the real-life superheroes who were the subject of her new book Good For Nothing. Also in the episode, we hear from Dr John Bradshaw, an anthrozoologist, about how deep our connection to our pets really goes… Hosted on Acast. See acast.com/privacy for more information. Learn more about your ad choices. Visit podcastchoices.com/adchoices

You said this place was steps from the water. We just haven't found the steps yet. How much did we save? Enough. Enough to get lost. Or you could book a stay with Hilton. Welcome to your oceanfront room. Just steps from the water.

The Hilton sale is on now. Book on Hilton.com or the Hilton app and save up to 20% to get the stay you expected. When you want savings, not surprises. It matters where you stay. Hilton, for the stay. Ambition comes in all shapes and sizes. At First Citizens Bank, we roll with your goals because we're built for what you're building.

Fit for your ambition for Citizens Bank. Peak pollination season, and my business is scaling fast. To keep the nectar flowing, I need a phone plan with top priority data speed. That's why I chose GoogleFi Wireless. My connections stay strong even when the hive is buzzing. Plus, unlimited plans started $35 a month. Now that's a deal that doesn't stay. Explore GoogleFi Wireless plans today.

Plus taxes and government fees. GoogleFi Wireless is not subject to data traffic deprioritization during times of high network usage. This podcast is sponsored by name, audio and focal. Streaming has made music more accessible than ever, but true listening is about more than ease. It's about quality. British audio experts name audio, alongside French acoustic specialist focal, combine handcrafted tradition with cutting-edge innovation and high-end materials, delivering digital precision with analog warmth.

So you can experience exceptional sound at home. Music just as the artist intended. Visit name audio.com to learn more. I was stranded in the middle of the night. I had no cell phone because this was back in the 90s. And I was sure I was going to die. Hello and welcome to the Science Focus podcast. I'm Daniel Bennett, the editor of BBC Focus.

magazine. In this episode, we dig into the psychology of people who risk their lives for total strangers. Until somebody has put their own life on a line who's a total stranger you to save your own life, you don't fully grasp the gravity and the magnitude of what a huge thing that is to do. And we talked to an anthropozoologist about why we keep pets. Keeping pets is not just a fashion. It's not just a fad. It's something which is intrinsic to many of us. You're listening to the Science Focus podcast from the BBC Focus magazine team.

With the UK's best-selling science and technology monthly, available in print and in several digital formats throughout the world. Find out more at sciencefocus.com or look out for us in your app store. When Dr Abigail Marsh was 19, a total stranger saved her life. Ever since then, Dr. Marsh spent her career studying the psychology of those who helped strangers. In the course of her work, she studied real-life heroes, who she describes as super altruists, who have donated their kidneys to strangers, and met people with psychopathic traits who show little empathy. A retortory assistant, James Lloyd, met with Dr. Marsh to talk about her new book, Good for Nothing,

which looks at the science of selfless acts. In your book, you describe some of the most extraordinary acts of altruism you've come across in your research. Could you give us a few examples of some of these? Sure. The population that I've been studying now for about seven years is a group of people who have done something I view as definitely extraordinary, which is they've donated one of their kidneys to a stranger. Wow. Yeah. Yeah, most of them learned about the need for kidneys. Kidney failure is the ninth leading cause of death in the U.S. right now.

And there's over 100,000 people currently waiting for a kidney. And I think a lot of people believe that, you know, enough people get kidneys from cadavers every year to meet the need. It's nowhere close. And in addition, kidneys from cadavers don't function nearly as well. And they learn about this and they decide in most cases more or less immediately that they would love to give one of their own kidneys to whoever on the list happens to need them. And so how many of these people if you come across that have donated kidneys to strangers? Well, the number that we have actually worked with in interviewed is around 50 or 60.

There are many more in the US, maybe somewhere around 2000 or so. And there is risk involved presumably. Well, it's time, obviously. There's presumably risks involved with the surgery, money, like travel expenses as well, I guess, lots of things that are. All of those things, yeah. So there was a paper that came out last year that estimated for the first time how much living kidney donors, all living kidney donors, because most living kidney donations

are from close family members or friends. And I always hasten to emphasize that that is also very altruistic. but it is different in a sense from giving to a stranger. So the average living kidney donor in the U.S. loses over $2,000 of money from their donation due to a combination of travel expenses and lost work and things. So it actually usually ends up costing donors quite a bit to donate their kidney and money costs them a lot of time.

There's a huge amount of testing that has to happen before the donation. And the recovery time is variable. It's hard to predict for any given person, but some people are, you know, say they bounce back within, you know, a couple weeks. Other people that can take quite a bit longer to feel like they're feeling back to normal and able to do their normal activities. The surgery itself is not considered a risky surgery, but it is surgery. And so the risk of death from surgery is below 1%, but it's, you know, maybe I think it's three in a thousand. That's not zero at all. And then there's all sorts of other potential risks of long-term serious outcomes

like worst cardiac outcomes, possible kidney failure. These are all risks that the kidney donors take. It's pretty wonderful. And when you speak to these people, what kind of reasons do they give for wanting to do this? This is what I have always found the most interesting, and it was somewhat unexpected. which is that when I've asked people, you know, why was it that you decided to donate a kidney? You know, they'll lay out the reasons. They'll say, I, you know, I heard about the need for kidneys or I saw a news article about somebody who received a kidney and I realized there's this need.

And so I decided to donate. And I say, okay, we go back a little bit. Please unpack for me that moment between when you learned this was something that you could do and that there's a need for and the decision to donate because, you know, many other people have that same information and don't make that. same decision. And then they say, that's what I don't understand. To me, that's the obvious decision. I don't understand why other people don't make the decision to donate. And so I think that that is really interesting. And it, I think, tells us a couple important things. One is that the decision to donate or not is happening on sort of an intuitive level. It's not sort of a rational cost-benefit analysis for the most part, because people don't have great access to why they make

the decisions they make. And the other thing it tells us is something that, you know, I've known from the research I do on people who are very un-altruistic, which is that people are different. You know, we often make the mistake of believing that our own sort of perspective on the world or our own emotional reactions to things are universal. And that's often not true. People really vary a lot.

Before we drill down a little bit more into what makes certain people extra altruistic. I also wanted to ask you about your own experiences because I read in your book that an extraordinary act of altruism actually kind of kick-started your own interest in the topic. Could you tell me a little bit about that as well? Absolutely. I was a college student. I was 19 and I was home from college for the summer and driving on the biggest freeway in Washington State to get home late at night. And a dog ran out in front of the road and front of me and I did the thing you're not supposed to do which is swerve to avoid it which was in you know my own very small way I suppose an act of altruism in itself and also you know not a

rational decision believe me but uh in any case the I hit the dog anyways which was awful and that and swerving sent the car uh swerving and then spinning across the freeway until it came to a rest in the fast lane of the freeway, facing backward and oncoming traffic. And then the engine died from, I assume, from spinning around. And so I was stranded in the middle of the night. I had no cell phone because this was back in the 90s. And I was sure I was going to die because where I was just past the crest of this sort of bridge. And so there was no shoulder that I could escape onto. I couldn't get the car to turn back on. And the cars and trucks that were coming toward me in the fast lane,

right in that lane were, could only see me when they were almost on top of me. And so they were all swerving at the last minute to avoid me, you know, huge semis. And it was awful. And then this guy suddenly appeared at the passenger side window, which was the side closest to the little tiny shoulder and said, he looked like you could do some help. And he, I don't know where he came from. I don't know anything about him. and but I said yeah I absolutely need some help and he said okay I'm going to need to get the driver's seat

and I had this moment of hesitation you know as my mom's car I was driving like oh no what what's you think and I'm like what well what I mean the thoughts are sort of muddled in the search of situation anyway so I moved into passenger seat he ran around the car so he had to get into traffic again and what he had done I figured out later was that he had parked on the opposite side of the freeway when he saw me so he that meant he'd run across the freeway in the middle of the night. Five lanes, I think. And anyways, he figured out that the car was still in drive, which is why I couldn't turn it back on again, got it going, and gunned us back across the freeway

and parked me behind his own car. And then, you know, he looked at me and I looked horrible. I was all shaken up and he said, do you need me to follow you a little way? Are you going to be able to get home okay? And I said, no, no, no, I'm okay. And he said, okay, you take care of yourself. And that was it.

He left. So you didn't know who he was? he didn't say anything about, you know, why he did that. He just kind of, he just disappears. Nothing, nothing. I, I, I lived to this day with a regret that I don't think I said thank you. And that I don't know anything about him and I can't, you know, sort of properly thank him. But, you know, having now worked with the altruist that I work with, I feel fairly confident that he wasn't looking for me to say thank you or do anything. He decided he wanted to help, so he did. And so he essentially put his life. in danger to save your life. That's the ultimate altruistic act, really, isn't it?

Absolutely. Absolutely. It was truly heroic. And so that got you thinking about altruism, did it, and about how people can show these extraordinary acts of kindness? Exactly. It's one thing to sort of know about altruism in the abstract or in theory, you know, people save other people's lives. But until somebody has put their own life on a line who's a total stranger you to save your own life, you don't, fully grasp the gravity and the magnitude of what a huge thing that is to do. But it is a real puzzle. You know, why would anybody do something like that?

It's the same question that the altruistic kidney donors tell me they get a lot. Why did you decide to do this? When to them, again, it seemed very obvious. And so right around that time, I started taking classes in psychology, and it was evident that psychology is the field that has the methods to try to start answering the question of why people have the ability to be altruistic and to care about people. Because from what I've read, apparently it's always been a bit of a mystery as a scientist. From an evolutionary kind of perspective, why we would help others when there's no gain to us?

It doesn't really make sense from a scientific perspective, at least. Right. It flies in the face of our sort of, sort of, mistake and view of human nature as fundamentally selfish, you know, the nature red and tooth and claw bit. It seems to make no sense from a sort of Darwinian perspective that anybody would sacrifice their own welfare to benefit a stranger. There's all sorts of good evolutionary explanations as to why people sacrifice to benefit others who are close to them, either genetically or socially.

That's not that hard to explain, thanks to, you know, wonderful work that's been done by people like Robert Trivers, but it's the sacrificing for strangers that always seems like the biggest mystery. So how did you go about investigating these super altruists then? So I thought a while about what would be a population of altruists that would be the best to study because there are many forms of altruism out there. And altruistic Kenyan donation had been in the news quite a bit at that point. Larissa McFarquhar had written this wonderful New Yorker article about altruistic kidney donation. And it was still a relatively recent phenomenon.

In fact, there were many transplant centers that didn't even allow it. And for most of the history of transplantation, it was not allowed to donate a kidney to a stranger because people assumed that anybody who wanted to must be insane looking to, you know, get money under the table or something. And, you know, the nice things about altruistic kidney donors is that there are sort of online lift serves and ways that you can contact them, ask if they'd like to participate. And so it's relatively easy to, or well, I would call it easy, but there was a way to reach out to this group of people. And then, of course, as I've come to work with kidney donors,

I've come to appreciate how important kidney donation is. And so I'm really glad to have worked with this very specific group of people because the need for kidneys is so great. So there's a lot of benefits of working with this population. And what kind of studies did you do, then was it like brain scans of these people or like kind of questionnaires or yeah so we brought them in to the lab here at georgetown we had to fly them from across the country because again it's a very rare population there aren't enough near georgetown um to study so we recruited nationwide and brought them in for hours and hours of testing several brain scans both structural and functional uh lots of behavioral testing just you know making sure that we had all

all the information about them that we might need to try to rule out hypotheses about them, but then also test our main hypotheses about them, which were derived from my research on people who are psychopathic, so who have very little empathy or care for others. And so the hypothesis we started out to test was that altruists would look the opposite of that population. And so what did you find out? Did you find kind of unusual things with these altruists? super altruists, I call them, that were different from, you know, like the average population.

We did, yeah, we recruited a population of local just controls who are just people who are similar to the altruistic kidney donors in every way in terms of, you know, age and gender breakdown and everything, but who have never donated a kidney. And relative to them, the altruistic kidney donors had three main characteristics that were what we had actually predicted, which is that they were more sensitive to other people's distress, and in particular they were better at recognizing other people's fearful facial expressions. That's interesting because that's something that people who are psychopathic, who are callous, are really bad at, is recognizing other people are frightened. And that's important because when you detect that somebody's in distress, and particularly

that they're frightened in most people that triggers a sort of spontaneous caring response. and that caring response, in theory, should stimulate the motivation to be altruistic. And so it makes sense that people who are altruistic are super sensitive to these cues. And then we found using our brain scans that the reason that they're more sensitive to these cues is that their amygdalas are more active when they see fearful expressions. And there's a long history of brain imaging that has demonstrated that the amygdala is particularly important for recognizing other people's fear. And in altruists, it's both more active in response to fear,

and it's also larger than average. So their amygdalas, the altruist amygdalas, were a little less than 10% larger on average than those of controls. Do we all have these responses then? But in these people that donate kidneys to strangers, they kind of turned up to 11 almost. Exactly. Yes, exactly.

So what it seems to be the case is given that we've got this population of people, who are psychopathic and are, you know, very uncaring about other people, that they are non-responsive to other people's fear and their amygdala's are underreactive and smaller than average. And then at the other end, we've got the altruists who have exactly the opposite of those traits, but that is consistent with is the idea that there's just a continuum of caring responses in the population that we're all somewhere on, you know, as, you know, is true for most continuas, most of us are sort of in the middle. So, we have the capacity to feel this caring altruistic motivation, but it's just not as robust

or as frequent as for the extraordinary altruists. You talked about there being a kind of spectrum of kindness from these super altruists on one end to the people who have kind of psychopathic traits on the other. Do you look at all the reasons for this spectrum, for this variation? Is it set by the environment? Is it a genetic thing? Or is it, as most things are, a mixture of both. Why does someone turn out to be a super altruist or turn out to be a psychopath? That's a great question. And one that my own research is only scratching the very surface of. There's been plenty of other good research out there looking at the reasons that people become psychopathic. And as you allude to, the evidence is pretty clear that it is a mixture of factors,

is that there's a pretty strong hereditary component to psychopathy with psychopathic traits, variation in psychopathic traits being accounted for maybe 60 or 70% of it by genetics, somewhere in that neighborhood. And the rest of it being accounted for by sort of idiosyncratic factors, nothing simple and straightforward like when you had a parent who was this way or that way, with a little bit of a little bit of room in there for parenting though to make a difference. So there is some very cool recent research showing that children who are genetically at risk for being psychopathic,

if they're raised by unusually responsive and warm parents, it cuts their risk quite a bit. So it's a mix of factors. And I will say that in talking to the altruists that I've worked with, there's no obvious variable that can predict, you know, that can discriminate. between extraordinary altruists and everybody else. Some of the things I get asked about are, for example, religious backgrounds. There's no one religious profile of altruists. I would say that we have more people who say that they are either Buddhist or sort of lean

towards Buddhism than you would expect in the U.S. And there's lots of good evidence that some Buddhist practices promote altruism. But there's no one answer to that question. And oftentimes, if I ask them, you know, why do you think you are the way you are, they'll say, well, it's how I was raised. Not everybody, but some. And then oftentimes I'll ask about if people have siblings. And I'll say, well, you know, do you have brothers and sisters? And if they say, yes, I say, well, did they turn out the way you did?

And they say, well, no. I'm the only one of my family who's like this. And so it's clearly not a simple parenting story. I would hate to leave anybody with a message that they as parents are responsible. for whether their children turn out very altruistic or not. It's really not as simple as that. Dr. Abigail Marsh there talking about the science of altruism. So the focus team are animal mad, like most of the UK, I suspect.

And for most of us, keeping a pet seems like second nature. But why are animal companions so universal in human culture? To find out, James Lloyd met Dr. John Bradshaw, an anthropologist based at the University of Bristol. His new book, The Animals Among Us, explores how deep our connection to our pets really is. And it reveals how our relationship with animals is actually one of the very things that makes us human.

So, John, pets can be quite expensive, they can be time-consuming, and they can often be quite smelly as well. So I was wondering, why do so many of us keep pets? What are the benefits to us? Well, that's a really interesting question. I think it's one that doesn't get asked very often because pets are kind of a ubiquitous feature of society. People argue about the details, you know, should you not have to scoop up after your dog in the park and that sort of thing.

But really take a step back to look at the whole thing in a more kind of broad context. So what is, you know, what is this strange thing we do? no other animal does it. There are a few kind of anecdotal accounts of lions adopting gazelle fawns and that sort of thing, but they're extremely unusual and odd. Whereas humans pretty much universally keep pets. It's not true of every society around the globe, but it's pretty much universal. When the pets are essentially unproductive, and that's a, has to be said, is a, you know, comparatively new phenomenon, most of the animals we have, and the dogs and cats that I look at most specifically in the book,

used to be, and still are in many parts of the world, pretty useful to us. So dogs have all sorts of different functions, they and still do, but for many of us nowadays, they're just companions. That's all they have to do. And the same applies to cats until maybe 50, 60 years ago, cats were regarded as being, you know,

as pest controllers first and pets second, if at all, and in many parts of the world, they're not pets, even in the United Kingdom. If you just step outside the cities and into the countryside, you'll find farms where there are cats that are kept very deliberately and looked after by the farmer, but are there not to provide any kind of company, but simply to keep rats and mice out of the feed stores. So it's a developing relationship and one that's developed particularly fast over the past few decades. which I suppose is not surprising since so many other things about society have changed a lot,

certainly over my lifetime. So the question is, I suppose, one way of putting it is, is this something which is just a hangover from our agricultural past when we needed those animals, very much needed them from an economic perspective, they actually helped us to thrive? and is it something which will then gradually disappear as technology comes to dominate our society, as it is, of course, on a daily basis, almost? Or is it something which is intrinsic to human nature and which we will carry on doing

because we enjoy it and there are no effective substitutes for it. It is something which we feel we need to do. And my inclination is towards the latter that keeping pets is not just, a fashion, it's not just a fad, it's something which is intrinsic to many of us. And I'd say that many of us, because clearly there are some people who don't feel the need to do it at all. And I think that's explainable in evolutionary terms as well. That brings me nicely to my next question, actually, because I was going to travel back in time a bit and have a look at our ancestors and how they might have kept pets. So how long have humans been keeping pets for? How far back in time

do we need to go to find the kind of first pet? Well, that's a very interesting question. Of course, the answer is probably that we don't know, but we do know quite a lot. We know quite a lot from hunter-gatherer societies that survived into the 19th and 20th centuries and could be documented by Westerners and were documented

and became the subject of much anthropological study. Anthropologists, unfortunately, unfortunately didn't concentrate very much on the animals that were around them. They kind of noted them down as they saw them, but only a few of those people actually documented these things in detail. So the evidence is a little bit more patchy than somebody like me would prefer. But it looks as though pet keeping in a rather different form was widespread throughout the globe. So we're talking about tribes that. that were discovered in New Guinea and in Amazonia and in Siberia. You know, it's not just at one particular location or anything like that. And some of those pets were dogs that had been introduced in by Westerners before the anthropologists arrived. But many of them were animals caught in the wild.

And those, of course, would vary from location to location, but they encompassed a very large number of species. the typical scenario would be that the men usually would go out hunting and bring back young animals that they'd captured in the course of the hunt and possibly their mothers as well, but usually just the young. And then those would be hand-raised in the village, largely by women and children, or typically by women and children, and treated pretty much like members of the family. So, you know, lived in the same huts and were fed the same food, or, a selection from the food that mothers were giving to their children and all that sort of thing.

So a very close relationship. And so this, if we can then extrapolate back from these societies, I think we can say, well, it's almost certainly, it seems very unlikely that all of these societies developed peckkeeping, having imitated it from Westerners, who they barely met and were very suspicious of, simultaneously in lots of different parts of the world. That doesn't seem like a very likely scenario. The most likely explanation for that is that this is a very very very important. ancient habit and had been going on for tens of thousands of years way back before the dawn of

agriculture. And the only other real piece of evidence we have is that it looks as if they were semi-domesticated wolves around around 30 to 35,000 years ago from the archaeological record. Whether those are the ancestors of today's dogs or not is unclear because there are big gaps in the records which last for thousands of years. And you kind of wouldn't expect those as if we'd been actually either be a continuous habit of dog keeping throughout that period of time. So maybe there were some failed attempts to get dogs out of wolves and then eventually about 15,000 years ago, the attempts were successful and gave rise to what we eventually turned into modern dogs. So, but there were, there would have been animals around. The fossil, well, the archaeological

record would not tell us anything because these animals, animals that were probably kept in villages 50,000 years ago would have been wild species. And so what was left behind after they died would have been indistinguishable from animals that people caught when they were out hunting. So it's difficult to know where the evidence would come from, direct evidence would come from. But I think it's reasonable to assume this is a very ancient habit. And it probably goes back to, as I explained in the book, and it's an ideal. that I got from a guy called Stephen Mithon, who's a professor at Reading,

is due to a change in the way that our ancestors thought about animals around 50,000 or so years ago, that we started to be able to imagine what it was like to be an animal. We didn't get it right, we don't get it right today, but we got it right enough to give us an advantage initially at hunting, and then probably the side effect of that was pet keeping. So presumably if going from a wild animal to a domesticated animal, there's a lot of time, I guess, and a lot of steps to go through for these animals. Could you just talk me through kind of the basic process of how an animal goes from being wild to being an animal that, you know, we keep inside our homes for companionship? Yes.

I mean, that's, again, shrouded. The early stages of that are prehistoric. And we know that really, we've had our ideas revised about that from new DNA evidence. that's come out over the past 20 years or so now, I guess, that the DNA of dogs, today's dogs, suggests a domestication point, i.e. a separation between the wild and the tame, the semi-dumisticated, around 15 to 20,000 years ago,

cats about 10,000 years ago, pigs about 7 or 8,000 years ago. These are all very early dates. And those are the things I think that need explaining. But I can come to that in a minute. I mean, after that, once you have an isolated population, that's the crucial thing. An isolated population, you can start to develop it

and change it into a domestic animal. Now, the initial stages of that, you know, 5,000 years ago even would have been, I think, pretty much hit and missed. So we're looking at a process which is much more like natural selection than the very deliberate breeding that you see in domestic breeds today where the mother and father are very carefully selected for their genetic qualities and so on for a very specific purpose, whether it's to produce lots of milk or to look like a pug or a Labrador, or whatever it might be. But that's done, I don't think

that's what happened was happening 5,000 years ago. I think what was happening then is that that animals were that were able to cope with being, with all the pressures of living with humans, which might be being kept in close proximity with others, so they're in kind being herded and so on, being in close proximity with humans, which, you know, not naturally they would have run away from in the wild. Those, essentially, the few individuals within those populations that had the right genetics to to deal with those pressures were the ones that survived. And the others either ran away or died, or at least failed to produce any offspring because stress is a big inhibitor of breathing in various ways. So natural selection would have in a kind of these animals would have adapted to themselves,

if you like, to a niche provided by humans, which we conceived of as exploiting them, and of course was at another level. And it was only the last two or three hundred years, probably, that the whole thing has become much more understood and organized and regimented. And I think, so I think the process of domestication changed from being much more natural to where most of the selection took place after an animal was born.

Is it going to stay and reproduce in the human environment, or is it not? Now we do all the selection. of the before the animal is even conceived, we choose the parents. But that's a big shift in the mechanism of domestication, and it's quite recent. And that takes me on to the next question again, actually, because I was going to ask, what do you think lies at the root of our desire to keep pets? Obviously, we've talked about quite a lot of reasons.

We've talked about the companionship, a possible way to beat loneliness, maybe even a way to connect with nature. But in the book, you kind of drill down deeper, and you say it's kind of wired into our brain. by evolution by our evolutionary past. Could you tell me a little bit more about the ways that our evolution as humans has kind of almost wired us to want to keep pets? I think there are probably two reasons why some people anyway evolved an ability to keep pets,

why people who were good at keeping pets prospered at the expense of those who didn't. And the first one is down to a colleague of one of Bristol, Elizabeth Paul, who's speculated that looking after, the way that somebody looks after animals, sometimes could be mainly women, but could also apply to men, is a proxy for a certain type of personality. So in those days, it looks as though marriages were organised by tribal elders, by either the parents of the couple or more senior people within the tribe, and that a lot of these marriages were essentially strategic. They were about intermarriage between neighbouring tribes,

which kept the levels of intertribal warfare down. And so people did not choose one other as marriage partners in the way that we expect them to be able to do today. It was a different kind of process. and so people might have been selected by their parents or others on the basis of compatible personalities. And particularly, you know, I want my daughter to marry a man who is gentle and good with animals or vice versa. That I want my son to marry somebody who's going to be good at bringing up children. And I see she can handle animals very well and bring up baby monkeys or toucans or whatever it happens to be that that tribe specialised in.

And so those kinds of people were preferred as marriage partners and so thrived at the expense of those who were much more kind of aggressive and hunting. And we see this. The reason we propose this is that we can see it today. One of the things strands in research into human-animal interactions that has been somewhat neglected, but it's always come up with the same results. is that the presence of animals makes people seem much more trustworthy. And so there have been experiments done where people have simply shown pictures of women, pictures of men with or without a dog and vice versa. And always just slipping a dog into the background in the photograph makes the person seem more trustworthy.

And there have been live experiments done where people have tried, they put a guy in a shopping mall in France and got him to chat up girls that were walking by with a very standard line. And he got a lot more telephone numbers when he had a dog with him than when he didn't. So there are numerous experiments like that done by different people around the world in different societies, so using different methods. So I think we can say this is a robust effect. So there does seem to be this trustworthiness component. And I think that's incidentally is why a lot of animal assisted therapy works, is that people who come into the hospital ward or whatever with an animal just instantly accepted in a way that that person who didn't have an animal might not be.

So I think that's one thing that they just say that we have to explain. Why are people with animals seem to be so much more trustworthy than people who don't have animals? And I think there's an evolutionary explanation to that, which is that their parents, their long-dince distant ancestors, were more reproductively successful than those who weren't. The other explanation, which I think is equally, well, I think perhaps is a bit more likely and certainly, again, a sort of thing that needs explaining, or explains an awkward, fact, which is that domestication of many species was so successful and so successful at such an early stage. So we now know from DNA that you can trace these domestications back way back before any kind of understanding of genetics. But I think even more importantly, before the invention of barbed wire or adequate fences to keep animals apart. Because the early domestic

animals would have behaved very much like their wild counterparts. And their wild certainly in terms of mating, there would have been no discrimination. I don't think a wild male would have turned his nose up at a domestic female or semi-domestic female. He would have just charged in and done what he needed to do. So keeping those, that unique and essential genetic pool of, which would have been a very small in number to begin with, keeping those separate from the wild. So it wasn't constantly being diluted with wild type genes would have been very difficult.

And I think pet keeping provides a psychological barrier, if you like, between the pet, the domestic animal and his wild brothers and sisters, literally, would have been the only one they could have had. They weren't able, wouldn't have been able to keep them indoors physically unless there had been a very strong emotional bond as well. And then secondly, we know that during that period of time, There were many ice ages. There were periods of famine. What was to stop the tribe from saying, excuse me, you've got some rather nice pigs living in your hut and we're hungry. We're going to eat them.

And thereby literally consuming all the genetic material that would otherwise have gone on to form the stock for domestication. And again, if those were personal animals, not simply commodities, that again, I think would help to explain that. that you're not asking to eat somebody's food, you're asking them to eat, you're asking if you can eat their friend. And the latter is harder to achieve than the former. Dr John Bradshaw there talking about why we keep pets. Thanks for listening to the Science Focus podcast.

In our December issue, which is on sale now, we report on the advent of personalised medicine and what that will mean for your health. We also take a look at the science of exploding head syndrome and we find out what happened when a scientist ate like a hunter-gatherer for a week and of course much more. Thank you for listening to the Science Focus podcast from the BBC Focus magazine team. We're the UK's best-selling science and technology monthly

available in print and in several digital formats throughout the world. Find out more at sciencefocus.com or look out for us in your app store. This podcast is sponsored by name, audio and focal. The texture and emotional depth of music can be lost through digital sources or poor signal. Name Audio believes you can have digital precision with analog warmth. Alongside French acoustic specialist vocal, Name creates high-end audio systems combining innovation with craftsmanship, so you can listen to music, just as the artist intended.

Discover more at nameaudio.com. Did you know if your windows are bare, indoor temperatures can go up 20 degrees, Get ahead of summer with custom window treatments like solar roller shades from blinds.com and save up to 45% during the Memorial Day Early Access Sale. Whether you want to DIY it or have a pro handle everything, we've got you. Free samples, real design experts, and zero pressure. Just help when you need it. Shop up to 45% off site wide right now during the early access Memorial Day sale at blinds.com.

Rules and restrictions apply. Hey, sweetie. Your mother showed me this Carvana thing for selling the car. I'm going to give it a try. Wish me luck. Me again, I put in the license plate. It gave me an offer. Unbelievable. Okay, I accepted the offer. They're picking it up Tuesday from the driveway. I haven't even left my chair. It's done. The car is gone. I'm holding a check. Anyway, Carvana. Give it a whirl. Love you. So good, you'll want to leave a voicemail about it. Sell your car today on...

Carvana. Pick up fees may apply.