 This is Twist this week in science interview episode recorded on Friday March 4th 2022 Why do we love? I'm dr. Kiki and today on the show. We will be filling your heads with the science of love and I would love to and invite you to enjoy this episode Welcome welcome welcome. We are here on the special Friday episode for an interview. Thank you for joining me today We're going to be discussing the science of love with Dr. Anna Machen who is an evolutionary Anthropologist at the University of Oxford written the book on why we love I mean, that's what it's called And We have a great show ahead I do hope that you will enjoy the conversation but as we get into everything I want to remind you that if you have not yet subscribed to this program as a podcast this week in science is available as a podcast all places podcasts are found We stream live weekly on Wednesdays at 8 p.m. Pacific time on YouTube Facebook and Twitch We are twist science on Twitch Twitter and Instagram all sorts of things to remember You can find information about the show at our website twist.org Okay, so now let's jump into this wonderful interview. Dr. Machen. I would love to Welcome you to our Friday interview program. Thank you so much for joining me today. Oh, thank you for having me on It's really exciting. Yeah, I'm absolutely thrilled to get to speak with you I mean, I wanted to get you in a conversation closer to Valentine's Day We're still within a couple of weeks. So I think What first got you interested in the question of why we love Enough that you wanted to study it because I mean as humans were all like, why do we love? Yeah, it kind of began a really long time ago long before I studied Alive humans So I did my PhD on the evolution of social and sexual behavior in the middle Pleistocene And the middle Pleistocene for those of you who aren't up on that particular period It's been about 1.8 million years ago and half million years ago But during that period lots of really exciting things in our social behavior began. We saw the formation of families We saw the evolution of fatherhood. We saw the evolution of the lots of cooperation And it was a really exciting time. And so I did my PhD on that and then I Basically turned up on the doorstep of Professor Robin Dunbar at Oxford University I taught his son at university and I turned up on this doorstep and I just went I really want to work with you And I'm basically not going anywhere. So he very he tolerated me And I kind of took up a place in his research group. We studied sort of Everything to do with the evolution and the neuroscience of social behavior So I had colleagues who were doing massive network sized global, you know, social networks But my job was to do dyadic relationship. So they're really close Relationships we have and that's basically love And I started where everybody starts when they do love with romantic love But as an anthropologist, I think my role is to really understand the totality of a trait or a behavior in humans And it quickly became apparent and just talking to my subjects that we experienced love in so many different ways And so my role was to really look at that full spectrum To understand what happens in our bodies and in our brains when we fall in love and to just get as big an Understanding of the complexity of love as we possibly could so explanations at every level of explanation I think that's doing the job properly as an anthropologist is to to get that totality of what's going on Right and at the beginning of your book the preface you say I'm not going to give you a simple answer to why we love And is that is that pretty much it? Why is there is there no simple answer? Do we have is it just so big? It's so big and the more you study it the bigger it kind of gets I mean you can stop start to narrow it down to factors But yeah, what I think is amazing about love and I say it in the book is I find it or Inspiring I find it or inspiring because it literally infiltrates every fiber of who are beings every mechanism in your body is involved in love And then if you think about your daily life Infiltrates all your daily life your daily decisions the interactions you have with other people So it's it's a really awe-inspiring thing And I think if we reduce it to one thing or two things and we try and find a formulae We're not doing it justice. So actually the book is about Explaining love in lots of different ways and if you put them all together, hopefully you get the 360 So there isn't one one answer to the question and that's that's what we have to address And I think sometimes people are disappointed Particularly when I do public talks and they think they turn up thinking right science is going to give me the answer And I'm going to go out here and I'm going to have really successful relationships And certainly we can tell you lots of wonderful things that are going to help you and really explain how you're feeling What's going on in your body? But I'm not going to give you a formula at the end saying if you do a plus b divided by c You know to the power of whatever everything's going to be fine because it doesn't work like that So I'm trained as a as a neuroscientist and I also trained my my undergraduate years as a conservation biologist and so I Am very science-oriented, but I come at it from that reductionist Perspective I think of when I think of love, you know I there's the human side the poet the the artist's creative side that I can appreciate as a human But when I come at it, I think about it very very Essentially as okay We've got molecules and electrical signals in the brain and the body and that is how we love Yeah, yeah, so can you help me and the audience kind of make that leap from how we love to the why we love? Well, yeah, I mean the book is sort of like the how why what where all those sorts of things I think Obviously the biological side of it the neuroscientific side of it is one of the really key important elements It certainly certainly is but how somebody experiences love and why they fall in love with a particular person Isn't just about that biological dimension So I I kind of you can reduce love down to two dimensions the biological and the social And the biological side we expand by looking at neuroscience. We expand by looking at genetics psychology You know pharmacology all these sorts of things and the book certainly does that Um, but there's also all those other things that come into why you fall in love So when you fall in love with somebody obviously all this wonderful stuff is happening in your brain your physiology Everything's keying in your sensors But also because we experience love at a very conscious level Also things come into your mind like what will my family think what will my friends think? What's my culture say about this? What does my religion say about this? What do my politics say about this? What are the laws around this? So when you decide who to love and how you're going to love and why you're going to love You're not just an automata a biological automaton doing all that you are bringing in all this other stuff Which is also going to decide Am I going to be in love with this person? And I think because I'm an anthropologist and therefore I'm a scientific end of anthropology But we are taught very much that that we have to understand the total human And not just part of the human and so I think that's that's the direction I come at it from so yeah My research work is in neuroscientific. It's genetic mainly But I also spend a lot of time talking to my participants just talking about Who they love what's their most powerful love? What do they think love is all these sorts of things and I think You only get the full experience when you get that side of it as well I think and I think that's it's my training to do it that way. I think What have been some of the most I guess insightful comments or or interesting Comments that have come out of interviews with with your subjects that have led you to think about things in a slightly different way I suppose there's there's several things that really From talking to people there are two things that really are amazing is first of all How many definitions of love there are so if you say to someone what is love? You get so many different definitions, you know, some people will take down that reductionist thing And I'll go it's just some neurocatheters in your brain And they will go down that route But then you will get people who who could write your whole essay on it or people who will just give you one word So some you know, one person just said to me friendship Or one person said to me understanding, you know or other people who will go on and on and on so first of all That really teaches you a lot about love because Ultimately how I love and how you love are going to be different And I will never experience love like you experience love And as a scientist I will never get to that absolute core of you I will be able to tell you lots of things about yourself about like let's look at your genotype Is it related to love and let's see what happens in your brain? What are your neurochemical levels and all this sort of thing? But there's a bit of your love I will never be able to touch and I think that bit is interesting um, I think the other things is just The sheer breadth of love that people can experience and there's so many different ways and how powerful it is And some of it's quite challenging For what they see as their most powerful love. So I spoke to nuns For the book and that's the looking at religious love. And this is the most amazing body of neuroscience of religion It's really interesting and but I was talking to them about their experience and trying to understand their relationships And I'll speak in one nun obviously we're used to nuns not have not having had You know romantic relationships are not having had children And in fact, I spoke to one nun who had quite rarely before she'd become a nun And I remember saying to her, okay, and I always ask all my interviews. What is the most powerful love you've experienced? And you get lots of different answers And as an anthropologist, you know, you have the poke face. You go, okay, that's great. Thank you very much She said so I said, what's your most powerful love? And I was expecting her like like a lot of people to say my children my grandchildren I don't know my You know my best friend and she just went God And for me that was quite challenging because I am a mum and It's a very powerful love and I was just like, oh my god, you literally you're putting god above all the others And that's quite challenging So you people would get you to look at love in a really different way same like I talked I spoke to polyamorous. I spoke to aromantics And they all made me look at love in a different way And I think that's the power of of talking to people about their love as well as yeah You know getting them to spit in tubes and looking at their genes Yeah Your your comment about the the nun is fascinating. My mother was christian scientist and at one point she She she started repeating the phrase very often god is love So that was just that was her powerful phrase. It was you know, not a question of what is what is god and that relationship It was she wasn't having a relationship with this Uh spiritual religious entity. It was Love and this is yeah much larger thing. And so yeah, yeah I I you know as growing up with that. I I think what you've said about the nun's Love of god being so powerful. Yes, so fine. So fascinating. Yeah. Yeah, absolutely. Absolutely But as you said being able to talk with all these different people about all this These different kinds of love Do they all impact us the same way so the love of a A partner the love in a polyamorous relationship the love of a friend the love of a child these are We can say to somebody I love you but i'm not in love with you Yeah, well, there are different sorts I mean, it's it's how you personally define love. So that that thing of I love you but i'm not in love with you What that sense to reflect quite a lot is The really intense lustful passionate bit of love, which is particularly there at the beginning Does fade and then you get some sort of companionate level of love Which is underpinned by slightly different neurochemistry And That is a very different feeling. So that's kind of the I love you but i'm not every single day Hungering for your love. I'm not, you know, like I like you feel for Hungry for food or thirsty for water. I'm not yearning for your love And that's that's generally that that's that phase where you've gone out of that lustful passionate bit, which I actually don't Define as love in my work. That's a very different thing into sort of companionate love And in terms of whether there are differences in the different sorts of love They're all underpinned by the same neurochemistry at different levels of intensity Obviously, the brain activations are different because they have different components to them but in terms of if we look at it in the evolutionary Phase of what are the benefits of love? Why did love evolve? The benefits of being in these relationships and having them underpinned by love are the same You know, we know today even though people I mean the very simple question to do the answer why we love Um answer to the question. Sorry. Why we love is survival. That's why we love Love at its most basic level and this is a nice hard scientific answer. Love is biological bribery. Love is what evolution came up with to make sure We cooperate with people because humans are unbelievably cooperative. We have to be cooperative to achieve so much You know to raise our children to do all the learning we need to learn to just function in this incredibly complex world Particularly as we keep on innovating things, you know to subsist and we need to do this for our survival If we don't do those things then our children don't aren't raised, you know We don't eat all these sorts of things trouble is as we all know cooperating with people is really really hard It's stressful. It can in fact threaten your survival anyway, particularly if you're if you're Assuming all your needs for somebody else's so You know evolution needs us to do this cooperation, but sometimes it's really hard And so we get rewarded and motivated by this wonderful flood of neurochemistry and that is the sensation of love Essentially now lust at the beginning is is underpinsed by a slightly different balance of those neurochemicals And then we go into love later on But so ultimately the benefits of love are the same it is your survival and even today people say yeah But it can't be about survival I you know I see in the environment in which we evolved that you know We probably needed to cooperate to you know find water sources for hunt for food Learn how to snap stone tools all these sorts of things But really today we I don't think so But actually this the most amazing body of work linking Love and having healthy relationships and having functioning relationships with other people and your mental and physical health And it's very very powerful to the extent that that and I agree with him My boss Robin Dunbar has argued that love and the nature of the relationships you have is the biggest factor In your healthy longevity and a life satisfaction above everything else If you do not have functioning relationships in your life Regardless of what basis they are regardless of what context they are You know whether they be with friends or family or lovers or whoever it might be Then that is to your detriment Quite severely to your detriment. So yeah Ultimately they all have the same benefit the questions we have going forward into the lesser areas that have been studied Is yes, so does religious love have exactly the same benefit where you're interacting with someone who doesn't manifest in physical form Does love for going forward, you know, there's a whole Dynamic of trying to develop social robots if we built friend relationships of robots Would we have the same benefit and that's kind of a question and we have to look into that But when we look at the standard human relationships, yes, they all have the same benefits really Yeah, and there is research suggesting that people who with um Spiritual religious beliefs that they have healthier mental states Absolutely Yeah, we need more more evidence on that but certainly that's where it seems to be pointing and it's not just because they get a community Right and some people like you get that you get that church community. Well, there we go But actually there is something about the relationship with a higher being They gives you a benefit. Yeah, and then you have to get into well. Is it correlation? Is it causation? Yeah, exactly. How do you tease that out and it's yeah exactly and it gets very complicated But that's kind of where we're at with that kind of work is is yeah What's going on there and is is that a real effect? Along the lines of uh, these relationships you in the book you do talk about the public versus the private aspects of Of love so like your personal private Love versus what happens in our culture and society and I was intrigued by some of the examples of different cultural practices and what are your what's one of your favorite? cultural rituals that you've come across I Related to love What I find amazing is is there's there's one particular Pakistani group that They have really interesting rules about the love for your child, which again, I find quite challenging Um, because you know in in the west we're all into you know You shower your child with love and it's attachment parenting and all this sort of thing and and you praise your child And they have the complete opposite that to show true love for your child is to restrain yourself from showing that love So you can shower the kid next door with love But you do not do that to your child because if you do that you bring the threat of the evil eye upon them And I just find that really interesting that so as a mother you actually have to fight your instinct Which your instinct is generally to bundle your child up and and comfort them and Sing their praises from the rooftops and do all those sorts of things That's not what you do and that shows the huge power of culture to work against What we are actually evolved to do and I think it's really really interesting Um, how strong it's like, you know the cultural ideas about You know monogamy and and that's why some people find polyamory so threatening Because actually it goes against our societal rules about how we should love Um, it's not actually based on any particular scientific evidence But it's based on the idea that you know, we all have we all pair up and that's what you do Yeah, it's a the the aspects of this how it all evolved, you know, if we come from our tribal Beginnings or the small groups It probably, you know, aside from coupling there were not those just the pairing up there was probably much more polyamorous or at least Less monogamous Relationships and much more social connection and maybe even more Group raising of children and so the like and and the question is how did we split off into all these different cultural Identities with these different Exactly. I mean and it's really interesting. I mean monogamy evolved in terms of what, you know, socially imposed monogamy and religiously imposed monogamy Very much as a form of social control. That's what it's about It's it's much easier if we know that everyone's going to pair up with one other person So we can keep controlling that we know if you just let everyone just do whatever they want Then we have chaos and then we can't cope with chaos So we'll so you know, we will have these rules where you know, you can only marry one person at a time and God says you can only marry these sorts of people and then that's nice and neat and everybody knows the rules Um, and that's that's a power thing. That's that's maintaining power over society when in fact, you know As you say in terms of where how we evolved We might have had a form of serial monogamy, particularly when we just maybe just had Tiny babies human babies as we all know are born far too early They need to have been in there a lot longer. So they're very very dependent and maybe far It's why human fatherhood evolved But maybe for a short period of time A pair of parents might stick together for a bit at that really tricky time to invest to make sure the kids survived But after that, you know, it's kind of like a free-for-all You know and certainly we have definitely evolved to raise our children as a community Not as not as two people Definitely and even in those worlds where we have this idea of the nuclear family If you think of the number of people have an input into your child's life Even if they're professionals teachers doctors That's all cooperating. That's all a cooperative raising of your child I wonder what if we were to Follow the biological aspects of love and let that dictate Our culture how much Different would our cultures look? That's really interesting. I think they would That's a really no one's ever asked me that for and that's a brilliant question. I think If we were less restrained I think there would be much more freedom to choose and to move quite fluidly between different relationship types You know, we have these rules about how you should be and and monogamy or whatever But I think maybe if we just followed what our instincts were and like, you know I'm attracted to this person say today. I'm having a relationship with this person Whether whatever their sexuality whatever their gender that's what I'm going with tomorrow I'm going to go and do this or you know for those people who Can cope with it with jealousy to the extent that they are very happy to be in polyamorous relationships I think you would see much more open behavior along those lines um Yeah, and I think you you would see the removal of those structures And you would see people following their instincts much much more. So it would be a much more fluid thing I think if we just followed our biology um I mean some of our biology, you know for some people isn't helpful um So, you know, but uh But in the long run, yeah, I think it would be a much more fluid and open Open way of being other people restraining themselves and working against some of their biology Right, and uh, there would be a reduction probably in that Societal control cultural control top down. Yes, which is okay Scare the people in power. No, they would no they would not like that. That would not be good um as you you mentioned also the the the positive mental health aspects of So of relationships all the relationships that we have and we're coming into a Like a lull point a dwell point in the covet 19 pandemic where Masks are starting to come off people are coming together again and socializing a lot more than they have over the last couple of years here in the united states People are going back to the offices and things are Going back to I'm not going to say going back to normal. They're they're they're going. Yeah Yeah So what have you seen over the last couple of years in terms of relationships and how they have affected Love and mental health how the pandemic affected that I think we all know the pandemic was not positive for our mental health and I think alongside the fear and You know listening to a lot of negative news the big thing that fed into that was the inability to have meaningful contact with those you love a meaningful contact with other people humans have evolved to Be with each other in person. We don't understand this screen this virtual relationship thing our brains have not evolved to deal with this So we need to be in the room and we need to you know Our the neurochemistry that's released when you interact with somebody Um is based upon touch. It's based upon laughter. It's based upon eye gaze It's based upon all these sorts of things and that's about being in the room with somebody And I think one of the most powerful things that showed to me how important love was was the concept of biobehavioral Synchrony and biobehavioral synchrony is something you observe when two people are interacting and and we all know that if two people are Close and they interact they kind of mirror each other's behavior And we kind of know that but if you look inside their bodies their physiology comes into synchrony as well So it started from different baselines But you get you know a synchrony and heart rate and blood pressure and body temperature And then if you look in the brain We get synchrony and neurochemical release and in brain activation And so every single mechanism in your body is coming together in one sense kind of making two people one person And I think that is very powerful and that underpins The benefits of love now if you are separate You do not get that you do not get that that amazing coming together of two people And that's people would often say, you know, I viscerally or I I feel I feel pain that I'm not holding my my loved ones I feel pain that I'm not with them. I can I can feel it as a physical Sensation and that is why is because you're not getting the biobehavioral synchrony You're not getting the positive neurochemistry. You're not getting the mental and physical benefits And that is I think why it hurts so much And I think in one sense I I write in the preface to the book that if any positive thing has come out of k-vid I think maybe it's a realization Which I really hope we hold on to of the importance of being with each other And of those you love and the support you get from them and acknowledging that Because that's what we were feeling. We were feeling that absolute absence Of this structure that underpins your life. It wasn't there anymore So, yeah from a k-vid point of view, it's it's been very interesting for those of you who study social behavior I'm sure they're going to be Research papers coming out for oh, yeah I said so many people to study You mentioned earlier different questions that uh Are still going, you know still having questions more questions about love even after studying it for years and writing this book um One that's interesting to me and I I don't know if you have any insight into this as also having been a primatologist But the question of do other animals feel love if it is For survival of social animals especially Would we expect to see The artifacts of love or things similar to love appear in animals that would give us an idea that Yes, they do love as well. Yeah I very strongly believe animals love as well I think the problem we have is we kind of hold animals to a higher level of proof than Then we do humans. So if I said to you Do you love that person over there and you said yes, I just believe you. Okay. You love that person You know, we don't believe that with an animal So we put we put these tests in place for animals So, you know, do they exhibit do they have the neurochemistry that we have that underpins it Do they exhibit attachment? Do they have empathy and what kind of what kind of empathy I'll be just talking like You know emotional empathy or emotional contagion. Are we talking full cognizant empathy? You know, um, do they have uh relationships beyond the reproductive? So do they have friends for example, do they experience grief which is obviously the absence of a so we set all these little Hurdles up and go right you've got to jump over all these hurdles And there's a lot of animals that jump over those hurdles So, you know, you particularly if you look at elephants, you know, the higher Elephants dolphins the apes monkeys dogs Meet some of them So there are a lot of animals that go over them, but even then you will get some people who's crawling on the book Okay cats cats. We're we're working on cats and I'm sure they do But um, but so we get them to go over all hurdles and then someone will go yes, but Yep, and that's the problem is that we said so I very strongly believe and there was a wonderful neuroscientist Who you might know called yeah panc set and he was an effective neuroscientist And he studied relationships and social behavior in a lot of mammals and what he said was Love is kind of like the cake And lots of animals have the cake But what we've done with human love is we've kind of decorated it on the top with all this other stuff Which is wonderful and gorgeous But not necessary to experience love. So we will say yeah, but you know Yeah, they don't abstract about their love and do they love in the absence of the other person and do they love in this And it's like yeah, but you don't need to do all that to experience love We've just got all that because we have this massive brain and obviously had a lot of time on our hands But actually it's the cake that matters and there are a lot of animals who have the cake I think in this case the cake is not a lie. The cake is love. Yes, absolutely I have I would love to continue talking with you about this But we are at our time and I don't want to keep you late on a Friday evening where you are So can we finish up with a just a couple of question very brief questions Your book why we love What do you hope that people can take from it into their own lives? I hope that they re-engage with all the different types of love in their lives We have a bit of a thing in the west of like privileging romantic love For example, I want you to go into your life and really look at and appreciate it and see where it all is Because actually it benefits you all there is no hierarchy of love There are they are all valuable And is there anything that we didn't touch on that you want to want to comment on before we go? I I yeah, I think just what's really interesting Also, I think is the science behind the individuality of love So in the book we go through a lot of the genetics that explain why people love differently And I think that's also a really fascinating areas We have universals, but there are also many things that make us different And we try I try in the book and really bring that out as to why we all love in a different way Why we love is available All over the world right now. Yeah, it is it's published in america. So that's the british cover There is an american cover, which is very pretty. Um, and yeah, so it's published in america as well And yes, it's available for for order for buying in bookstores if you go to bookstores Which people are doing more and more often these days. Yep and I've really enjoyed getting to speak with you about this and And reading through your book it's so full of interesting stories and interesting science that That I've I've quite enjoyed so thank you very much for joining me today. Thank you. Thank you so much for joining me Thank you And everyone out there, thank you for joining me for this interview I do hope that you will join us again for another Friday fun interview because more and more are getting scheduled This week in science does air like I said weekly 8 p.m. Pacific time On wednesday nights on youtube facebook and twitch and if you have learned anything from the show remember It's all in your head