Nicholas Christakis: The Science of Human Connection

Transcript

Harlan Krumholz: Welcome to Health & Veritas. I’m Harlan Krumholz.

Howard Forman: And I’m Howie Forman. We’re physicians and professors at Yale University, and we’re trying to get closer to the truth about health and healthcare. Our guest today is Dr. Nicholas Christakis, but first we always like to check in on current or hot topics in health and healthcare. Harlan, what do you have today?

Harlan Krumholz: Well, there’s so much going on, Howie, as usual. I thought I would just take a little bit of time to talk about this Retatrutide, this “triple-G” drug that Lilly’s come out with because there was some big news this week. They reported the results of the TRIUMPH-1 study, a Phase 3 trial in adults with obesity and overweight without diabetes. And in this study, in this study, so this is the new drug. When people talk about GLP-1s, well, that was kind of the first-generation semaglutide. And then tirzepatide came out with two drugs in it, two G drugs. It was GLP-1s and GIP. And now this is the triple-G drug because it adds glucagon. So it’s sort of continuing to add these agents to see if they can get a more powerful effect. And in this one, they assigned the patients to various doses, and these are patients many of whom were quite severely obese.

They had a severe obesity. Ania’s teaching me how to say this right. When we think about this as a disease, we want to talk about “people with obesity,” not “people who are obese.” And we never say “morbidly obese” again, because it feels so disrespectful. We’re trying to reframe this now. But in this, the people who are on the highest dose, this 12-milligram dose, lost an average of 70 pounds or almost 30% of their body weight over 80 weeks. And I think importantly, because people are now talking a lot about variation in response, nearly half of them achieved at least a 30% weight loss. And in a pre-specified extension among participants who had a BMI of at least 35, and that’s a pretty big number. But among those who tolerated and continued therapy, average weight loss reached 85 pounds or 30% at more than 100 weeks in, so more than two years, just about two years.

And it’s important to say what’s new here. Retatrutide itself has been sort of tested before. We saw a striking Phase 2 study. Now, these Phase 3 studies are larger. They’re regulatory pivotal. They’re used for approval of the drug. Phase 2 are kind of a little bit smaller, kind of gaining momentum towards the definitive study. Now that Phase 2 trial was published in The New England Journal of Medicine, led by our own Ania Jastreboff, been on the podcast, good friend. She’s doing great work. She’s also leading this TRIUMPH-1 study. And in that one, it produced a dose-dependent weight loss up to about 25% at 48 weeks in that 12-milligram group, that group that was at the highest dose. And so since then, there’s been other studies too that have looked at this, for example, in people with knee arthritis and in people with type 2 diabetes.

So this is extending it now to the large group of people who have obesity but without diabetes. And I think what made this one so impressive was the length of time that they were covered and the amount of weight loss. And so this is going to be presented at the ADA, the American Diabetes Association Scientific Sessions and without a doubt, it’d be published in The New England Journal of Medicine, I’m sure it will be. And I’m sure Ania would be playing a key role in this. I think this is just again, a drumbeat of good news. Now there was some caveats here. The side effect profile here was a little bit worse than what you’re seeing in the GLP-1 or tirzepatide, the GLP-1 and the GIP drug.

And so there are a little bit of concerns about, but it was about 11% of people had some kind of these side effects. Most of them are just nuisance side effects. In some cases it led people to discontinue them, mostly gastrointestinal, nausea, diarrhea, constipation, vomiting. Discontinuation due to these adverse events were about 11% at 12 milligrams compared to 5% with placebo. Now, that’s so interesting. People on placebo would still discontinue the drug. So no drug, essentially, they’re taking. They’re taking nothing.

Howard Forman: That’s why we like the placebo trials.

Harlan Krumholz: So 5%. So you’re doubling that, but the excess is about 6%, 5% or 6%. So one in 20, actually more people on this tended to discontinue was 11% overall. There were some other kind of weird things like abnormal skin sensations and a few people, urinary tract infections which hadn’t been reported before with these kind of drugs. So it’s not really clear whether this is a big thing. But anyway, this is still investigational. It’s not approved by the FDA, but I will tell you it’s on track to be approved. And so there will be, I think, a major step forward because this is really putting the drugs on par with bariatric surgery. Bariatric surgery was still able to get more than what we were getting out of the drugs before. This is going to level the playing field.

And so I think that this is going to be a big deal for people who are in a position where they’re struggling with obesity and they want to really improve their cardiometabolic health, and this will be a path. Now the only other thing to say is, these are all about weight right now. The question will be, what about cardiovascular outcomes? And those studies will come. But there’s a full expectation, given what the other studies have shown, that this will likely be positive, but we’re going to need to see that. But anyway, I just wanted to share that.

Howard Forman: Yeah. And look, more drugs in the market, even if it’s from Eli Lilly, means more competition over time and it may drive down price. And that’s also a good thing because it may make it more accessible to more people.

Harlan Krumholz: There are almost 100 drugs in the pipeline now. You know what’s so interesting is, I thought that with the success of these drugs and some of them turning generic, and as you know, in some countries like even now like India, I mean, it’s completely generic, everyone wouldn’t tack here, but in fact, there are so many candidate drugs that are in the pipeline. It’s going to be very interesting to see how all this plays out.

Howard Forman: Yeah. For some of them, the marginal cost is going to be dollars per dose. So it really does become affordable and it’s great. Thanks for that update.

Harlan Krumholz: And as they go from injections to pills, the pills are much cheaper to make.

Howard Forman: Yes.

Harlan Krumholz: We’re already seeing a big uptake, big uptake now on the GLP-1 pills. All right. Hey, let’s get to our interview with Nicholas Christakis. It’s going to be great.

Howard Forman: Dr. Nicholas Christakis is a sociologist and physician who serves as the Sterling Professor of Social and Natural Science at Yale University, Director of the Human Nature Lab at Yale and Co-director of the Yale Institute for Network Science. His research focuses on how social networks form and their effects on human welfare across social, economic, biological, and evolutionary domains. He has been elected to the National Academy of Medicine, the National Academy of Sciences, and the American Academy of Arts and Sciences, and has authored several books that have brought his research to a broad public audience. He earned his bachelor’s degree in biology from Yale University, his MD and his MPH from Harvard, and a PhD in sociology from the University of Pennsylvania, which is when I first met him.

This is the second time on the podcast. So first of all, I just want to welcome you back. I want to start off and highlight that your book Blueprint, which has now been out for I think seven years, still resonates really strongly with me at a time when the world is so divided and divisive. And I just thought we might start off with that because I think it gives a very optimistic view of the world, at least to me, when you think about over long periods of time, how humans have interacted with one another and whether we’re leading inexorably to decline and division or whether there’s hope for the future.

Nicholas Christakis: Well, first of all, thank you both for having me back. Brother, it’s good to be back. I mean, it’s hard to summarize that whole book. It was a labor of love. It took 10 years to write. The subtitle says it all, “The Evolutionary Origins of a Good Society,” and it’s very much focused on human capacity for things like friendship and love and cooperation and teaching and all of these wonderful qualities, which I think our species has, which are actually quite remarkable when seen in comparison to other species. I think for too long, both scientists and people on the street, the so-called man or woman on the street have been overly focused on the dark side of human nature and have neglected the bright side. Because if every time I came near you, you lied to me or you stole from me or you injured me or you killed me, I would be better off, we would all be better off, living atomistically.

So it must be the case that the benefits of a connected life outweigh the costs and that natural selection has shaped us, has endowed us with the capacity for living in a social state. It has given us these abilities, these qualities, which I think are quite remarkable and which are optimistically inflected. They are mostly good qualities. So that’s what the book is about, and it also plays to my own optimism about human beings and my own optimistic personality. So it was a pleasure to work on that book.

Howard Forman: But just as a quick follow-up, you actually use several different narratives to explain how people naturally come together in many different circumstances. Do you want to just offer the listeners one or two anecdotes, or maybe they’re not anecdotes, but observations that were made in the book over long periods of time in history? And you delved very deeply into these to explain how humans work together naturally.

Nicholas Christakis: Yeah. So the book opens with a kind of thought experiment about what would be, if you were a mad scientist, what would you do to try to prove through some of these claims? So what you would ideally love to do is take a set of babies and abandon them on an isolated island with plenty of resources and somehow contrive for them to be raised without being encultured in any way and then come back and see what kind of social order did they make for themselves. Just like for example, a child just raised in a kind of natural way, neither starved nor overfed, will grow up to have a pancreas and a kidney that work in a very predetermined, genetically prescribed way. So by analogy, what would be the kind of society we would make for ourselves? And of course, conducting such an experiment is impossible.

It’s unethical, it’s not feasible, but it hasn’t stopped monarchs from imagining such an experiment for millennia. In fact, it’s been called the forbidden experiment. Now usually I think the first example of this was Psamtik I, I think, like 3,000 years ago, we have records of imagining such an experiment and usually these monarchs have wondered what kind of language would humans speak if they weren’t taught to speak? And allegedly these monarchs contrived to have, let’s say, two babies given to a shepherd, a mute shepherd to be raised in isolation, and then see what kind of language did they develop. And actually I forgot which, James IV, I think it was of Scotland in the 15th century. I may have these facts garbled at this point, but I think he asked the question, “What kind of language did Adam and Eve speak?” So he allegedly did this experiment and then when they came back years later, allegedly the children spoke passable Hebrew. So this was the conclusion about what Adam and Eve spoke. So the point is, if you were mad scientists, you would like to do such an experiment, but of course we cannot.

So we have to look for natural proxies for that. And one of the ideas that I hit upon was to look at shipwrecks. So the book opens with a discussion of I think it was 19 or I forgot how many, maybe 20 shipwrecks where at least 19 people had been abandoned or found themselves for at least two months on a distant island. This was between 1500 and 1900. So I looked at all available records for 7,000 shipwrecks. I isolated down to this and then I studied these shipwrecks in detail and I combined that information about shipwrecks with many other sources of information, communes and kibbutzes that people had, for thousands of years, people have said, “Society’s screwed up. Let’s just go and start it again.”

We have records from Roman times of these efforts. I combined it with modern utopian movements. I combined it with data from scientists living on the South Pole in isolation or nuclear sub crews or miners trapped underground or online video games where in theory we could assemble any kind of social order. And across all of these examples, what I was able to persuade myself, and I hope readers, was that there is only one way to be social. That no matter what kind of situation we’re put in, we manifest these fundamental qualities, what I call the social suite, a friend, a certain kind of network patterns, a certain kind of cooperation, a certain kind of ability to communicate our identity, a certain kind of mild hierarchy, all of these qualities which are interconnected and which we are genetically predisposed to make, we manifest it across all of these many examples to the exclusion of other theoretically possible forms of social order which we don’t make. Anyway, and I go into that, that’s the beginning, let’s say, quarter of the book.

Harlan Krumholz: So what is it exactly that we should be doing that can bend the arc of history toward all of these kind of social attributes where we see each other as all part of the same family? How do we elicit this kind of response in a way that doesn’t disadvantage people but advantages them? I mean, I think sometimes people feel it’s a free rider issue or if I do something, what’s going to be in it for me? I mean, society tilts in that direction sometimes, but there’s just as much good going on all the time, but how do we ultimately get there? Some people accused you of being utopian in this book, that you were espousing ideas that really weren’t ever going to really manifest. And so as you’ve thought about it, given what’s going on today, what do we do to try to bend ourselves into that direction?

Nicholas Christakis: Well, first of all, I appreciate what you’re saying, but first of all, I think you’re right. You’ve identified a kind of liberal philosophy that undergirds the book, which is a kind of commitment to our common humanity. And I think that cultivating that perception—

Harlan Krumholz: And liberal, not in the sense of liberal versus conservative, but liberal in its—

Nicholas Christakis: Classically liberal. Yeah.

Harlan Krumholz: Classically.

Nicholas Christakis: Like humanitarian. Yeah, that’s right. Like an Enlightenment commitment to the recognition that all human beings share common humanity and that that’s worth revering and worth respecting. And one of the anecdotes I use in the book is that we have friends with each other, which by the way, is a very unusual phenotype. We form long-term non-reproductive volitional unions with unrelated conspecifics. Namely, we have friends. And this is very rare in the animal kingdom. We do it, certain other primates do it, elephants do it, and certain cetacean species do it. So other animals form relationships, but they’re often with their genetic kin. We form long-term relationships with genetically unrelated individuals. We have friendships, and most listeners take this for granted, but it’s actually a very interesting and deep phenotype.

So now I’ve gone off on a bit of a tangent, but I’ll come back to our common humanity. And so the point is is that if we can share the capacity for friendship with animals, with like elephants, then surely we can share it with each other. The recognition that every human being on the planet has this innate capacity, desire, that we all of us together have this patrimony, provides a kind of scientific foundation for a kind of ideological commitment that we human beings share this common humanity. Which is a pleasing, I think, at least philosophical stance, at least for me. So you’re right to highlight that that is one of the sort of animating ideas in the book.

But going back to the other part, people like Steven Pinker and others have argued, correctly in my view, that one of the fundamental drivers of our health and wealth today is the turn that was made during the Enlightenment, both the philosophical turn, so the kind of Enlightenment ideas about a commitment to democracy, to reason, to our common humanity, unevenly applied at first, of course. It took a while for women to be seen as participants in this thing and so on, but these ideas, which these philosophical ideas, which were propounded two to three hundred years ago and began to spread, the anti-slavery movement begins in England and starts spreading around the world.

So these philosophical ideas, Pinker argues, coupled with scientific advances, the discovery of electricity and magnetism and the steam engine and so on, contribute to, over the last few hundred years, making the world freer and more peaceful and richer and healthier. And I think Pinker is right. I think Steven is right in those arguments, but my argument is, we don’t just need to rely on such recent historical forces propelling a good society. Deeper, more ancient, more powerful forces operating over hundreds of thousands of years have been propelling us, have been providing us with the ability to create a good society, to actually love each other, as I argue, or befriend each other, at a minimum.

So my argument is that the arc of our evolutionary history is long, but it bends towards goodness. And I say this even though I recognize that every millennium, every century is replete with horrors, with slavery, with colonialism, with pogroms, with a Holocaust, with brutal violence and stupid wars, but equally we are endowed with these wonderful qualities and that on balance over time, I think almost like in Star Wars, the forces of light will win over the forces of darkness.

Howard Forman: I want to pivot to the YouTube series that you started because that sort of came out of nowhere for me. I started watching them because you posted them to LinkedIn. You only launched this a few months ago. I think everybody should be watching it. What prompted you to do it, and what are your hopes for this series? And give us an idea of which are your favorite episodes, but I could tell you which are mine.

Nicholas Christakis: Well, like you guys and probably many listeners, I’ve been very concerned by the rising tide of unreason in the world today and the rising authoritarianism in many parts of the world, including in our own country and the kind of almost deliberate destruction of science, which I think most people would credibly believe that science is a hallmark of our civilization, that it lies at the core of our wealth and our health and our security. Any listener who has a loved one that’s been treated for a serious illness, whose life has been saved or any listener that is able to feed themselves by spending 5% or 10% of their income every year instead of 40% or 50%, which is what we had to spend even 100 years ago of a median family’s annual income was spent on food. But now we can spend much less of our annual income on food.

Why? Because of science. Or any listener who feels secure in our borders, for example. I mean, we have to admit that our weapons are based on our scientific progress. So science both reflects our values, it reflects our commitment to reason, it reflects our wealth. We have the ability to allocate resources, not just defeating ourselves, but to actually engaging in human curiosity. It is also simultaneously a reflection of our values and our wealth but a source of what I would regard to be our wealth and our power and a supporter of our values. And therefore, I see the attack on science that is so widespread around the world today, including in our own country, shamefully, as something that needs to be resisted. And each of us, what can we do for this? I mean, I’m voting, I’m giving money to causes that I think matter, but I thought I could maybe launch a kind of YouTube channel that was about not the content of science but the craft of science.

And it’s sort of targeted at 18- to 30-year-olds interested in careers in science. But I think some of the episodes would appeal to anybody that is interested in any kind of the New York Times reader, the Atlantic reader, the Wall Street Journal reader, someone that’s interested in these topics. So it’s pitched at that level. They’re short, three- to six-minute videos typically released weekly about the craft of science and it has everything from the sublime to the mundane. So I talk about the feeling of discovery, what it feels like to actually make a discovery, which is just an extraordinary feeling, or what to do if your work is abused, you know, if you’re a scientist and your work is abused, or what was it like, as in my case, to teach students in a bomb shelter in Ukraine during this last fall. Why is it that, learning in a time of war, what does it say about our common humanity?

This desire that human beings have, to learn even in a time of war, again, illustrates the point Harlan was making earlier about our common humanity. So it has those kind of episodes, but then it has episodes on how to write an email, how to cope with rejection, why you have to work long hours as a scientist, how you cope with the feeling of autonomy. It can be very alienating for a young... it’s magnificent. The amount of autonomy you have as a scientist to pursue your curiosity is terrific, but for a young scientist, it can be very scary, like, “I want someone to tell me what to do.” So the episodes try to cover all of these topics, and they’re produced by Andrew Jordan, who is a young filmmaker that I recruited for this.

And soon we’re going to be expanding, in fact, I’m going to hit you guys up, we’re going to be expanding to other voices and other scientists around the world. So later this year, we’ve already begun this process of... and they’re not focused on the content of science so much. They’re not about scientific topics, although they do talk about that. They’re about the craft of science, how to do science.

Howard Forman: I mean, they’re very approachable and I definitely recommend our listeners to look. They’re a YouTube channel, For the Love of Science, and we’ll have it in the show notes.

Harlan Krumholz: Speaking about this issue of discovery, it’s almost the 20th anniversary of one of the most profound things that you’ve done. Well, you’ve done so many cool things, but this one I thought was really of course relevant to the kind of work I do, which was your famous paper with James Fowler in the 2007 New England Journal of Medicine about the spread of obesity in a large social network. I think it was revolutionary at the time because people didn’t really think about obesity as, in essence, a communicable disease. And you followed these people from Framingham Heart Study over time and saw that a person’s chance of becoming obese increased if a friend became obese in a given interval and it was even stronger than if a sibling became obese and a spouse, again, not connected biologically, was also related. And it was just such fresh thinking and it was so important. I think when you look back on it now, what do you think people understood correctly about it? Have you reassessed it? I mean, is your thoughts about this refined over time? It was such an important piece.

Nicholas Christakis: Well, I mean, I’ve spent the last 25 years of my life. I mean, my life’s work has been studying human social interactions in all aspects of this. So we started with some observational studies 30 years ago to 20 years ago and then quickly moved to experimental studies. So the 2007 paper you mentioned was an observational study, but by 2010 we were already doing experiments and publishing them, documenting social contagions. Showing for example, that people’s so-called public goods production, their altruism, their willingness to help others could be shown experimentally to spread within social networks and doing field trials in Honduras and in India and in Uganda around the world, showing that we could exploit an understanding of human social network structure and function to pick particular individuals within social networks. So if you have a village and you can pick five women in this village to teach them about breastfeeding, which five should you pick such that if you persuade them to breastfeed their children, everyone else in the village will copy them?

So we took social contagion very seriously. And interestingly, in that 2007 paper, we also spoke a little bit about the possibility of biological contagion of obesity, that maybe there were commensal microbes within us. So we documented the spread. We suggested it was mostly social, but thankfully there was a little wrinkle in that paper where I said, “Well, this does not exclude the possibility that there could also be viruses or bacteria that spread from person to person that affect their body size.” And that’s something we’ve also kept in mind and returned to. So we just published a paper in—

Harlan Krumholz: Oh, that’s so interesting, because that really presaged all the microbiome work. I mean, it wasn’t really, in 2007, understood to any extent, not that we really were still understanding it, but that was an extraordinary thing for you to posit really at that time.

Nicholas Christakis: Yes. So we did. There’s a sentence in the discussion and then we returned to that. It took me like 15 years. In fact, to study that was one of the reasons I moved from Harvard to Yale because I needed a wet lab to study that, and Yale was willing to give me a wet lab. And it took a long time. We had to collect stool specimens from thousands of people in Honduras and then show that there was a spread of the microbiome from person to person and person to person to person within these social networks. So the idea here is, and it’s an interesting idea for listeners to contemplate, there are many other laboratories—not mine—which have shown that bacteria within us can be associated with certain diseases like obesity or conditions like obesity or depression or hypertension, Harlan, or arthritis. So the bacteria within you may produce substances that go into your bloodstream or stimulate your immune system in such a fashion as to cause these conditions such as depression, obesity, hypertension, or arthritis, for example.

And our work has showed that these microbes can spread through social networks so that when I shake your hand, for example, microbes from me go into you. Well, if you put those things together, what it suggests is that we may be in an era where we are discovering that diseases that were formerly thought to be noncommunicable might actually be communicable, that depression might be communicable and so on. And in fact, we published using the Framingham Heart Study data on the social contagion of depression, and most people understand that there’s emotional contagion. This is not a shocking allegation, that your mood depends on the moods of others, but actually to the extent that some of that is due to the spread of the microbiome from person to person, that’s a pretty radical innovation. And I think that’s true. And by the way, one other crazy idea that I think is also true is that many laboratories have shown that genes are associated with various sorts of outcomes like gambling, for example, or depression or risk-taking.

So all of these behavioral phenotypes, we know there are genetic predicates. And we have shown that networks might be associated with these things, like how kind you are to others or how depressed you are depends on how the people around you treat you, whether they are kind to you or whether they are depressed and so on. But now we’re also showing that these genes are associated with your social network structure, in another line of work in my lab that shows that genotypes can affect, for example, how many friends you have or how you pick your friends. So what this means is that one of the ways that genes may make you depressed is not by what they do inside your body by modifying your brain chemistry but what they do outside your body by who you pick as your friends and by how many friends you pick, for example.

And so therefore it means that the geneticists’ understanding is misspecified. When you say, “Oh, these genes place you at risk for this outcome like depression.” Actually it is folding in another pathway that is being neglected and overestimating the endogenous pathway to the exclusion of the outside-your-body exogenous pathway. So all of these ideas about the communicability of noncommunicable diseases, about the ways in which genes can shape our behaviors and therefore our minds, I think are really frontier questions that are going to be addressed. And my group is trying to contribute some foundational papers that help shape that discourse.

Harlan Krumholz: Yeah. I mean, you’re just identifying these targets of intervention don’t necessarily have to be at the gene level. I mean, and ignore their gene products, but that there are other places to intervene that could basically preempt the adverse events or promote the positive outcomes.

Nicholas Christakis: Yes. And a lot of this stuff is probably going to just provide support. For example, keeping with the depression example, for things that are already known, depressed people benefit from reduce their social interactions and seem to benefit from social interactions. So maybe it’s not that their serotonin levels need to be adjusted in their brains; they just need to get out and exercise.

Harlan Krumholz: But this also opens up this issue about assimilation. People leave their cultures, they enter a new culture. It’s not just that they’re exposed to different foods or environment, but actually the way you’re talking about it, it could be that with the new cluster of friends, new environments, it’s both being mediated at a biological and a social level. I mean, we always thought of it more as a social assimilation.

Nicholas Christakis: I think that’s right. So I think when you look at some of the old studies on, for example, changing cancerous—you know, those famous studies about the Japanese—

Harlan Krumholz: The big cardiovascular studies, whether Japan, to Hawaii—

Nicholas Christakis: Yes.

Harlan Krumholz: to the Western—

Howard Forman: Prostate cancer also. Yeah.

Nicholas Christakis: Yes. And stomach cancer, I think is the classic one. You guys may remember these a little bit better than me, but I think part of that has to do with the dietary changes affecting the microbiome. And I think you coevolved over centuries with a certain food environment, and I think that could change the microbiome within you and then contribute to some of these other things. So there’s no doubt that a lot of these things are going to be worked out. But my contribution, the thing we’re working on, is the social contact aspects of that, how the interactions between people may play into these very deep broad questions that are being asked these days. So going back to the 2007 paper, I reread the paper like a year ago. I stand behind everything in that paper. I think it was carefully worded. We did the best that could be done with statistical methods at the time.

The paper was criticized by people who said, “Well, these methods were not optimal.” But they didn’t have any better methods to suggest, then or now. Actually, now there are better methods, 20 years later. And we very quickly moved to doing experiments, which further supported the whole claim about social contagion. There was actually just an article. In 2008, we published a paper in The New England Journal on smoking and there was just a paper in Science this past month where people used Add Health data to reproduce our results on three degrees of separation. So we showed, for instance, in the 2007 obesity paper and the 2008 smoking paper, and then in other papers as well, including using experiments, I keep mentioning this, that your peer effects don’t just stop at one degree of separation.

When you make an action like lose weight or gain weight or quit smoking or act kindly or vote or start breastfeeding your kids, it affects your friends, but also, weakly still, your friends’ friends and even your friends’ friends’ friends. And now repeatedly using observational experimental data, we’ve provided evidence for what we call the three degrees of influence rule, which is that all of us are kind of shaped by and shaping a kind of social zone that’s up to three degrees removed from us.

Howard Forman: I don’t want to let us end without hearing more about the trip to Kyiv that you took in the fall. You mentioned it briefly in an earlier segment, but that must have been an emotionally and physically shocking visit because you’re visiting a university in the time of war. Can you speak more to what that was like?

Nicholas Christakis: They invited me to go and I struggled with whether to accept the invitation. My wife was sort of against it. She thought it would be unsafe, but I really struggled to see how I could say no. I mean, these people were inviting me to spend a few days in a very fancy hotel in downtown Kyiv with a good bomb shelter and give a few lectures. And how would I tell these men and women that I was unwilling to visit their city even under those circumstances in which they had to live all the time? Like, “Your city is too dangerous for me to visit, but it’s fine for you to live in.” I mean, it just didn’t make any sense to me that I would have to say that. And when I got there, it was just surreal. This was a big swanky hotel and there were, an air raid started soon after I arrived and I had this little app which was notifying me and buzzing.

And then you hear the sirens outside and the app is buzzing and there were men with flak jackets and machine guns in the lobby and workers and guys with suits, probably spies, and waiters traversing the lobby with not white gloves but white aprons and stuff. And I’m sitting there and it’s like being in Rick’s Café in Casablanca. There’s a woman playing a saxophone, playing “La Vie en Rose” with an Apple computer backup band because all the male musicians I imagine are on the front, and I’m thinking, “This is insane.” I couldn’t even believe I was there.

And then my host comes to pick me up and she came to meet me, I don’t remember, around six and we had to go to the university, and the air raid is blaring and I say to her, “Well, how can we leave the hotel? There’s an air raid.” And she goes, “Ah, that’s just a little Shahed drone.” I was like, “Well, how do you know that it’s a Shahed drone?” She goes, “Oh, well, I’m on this Telegram channel.” And they had made a—basically, the inventive Ukrainians had basically made a Waze for missiles and drone. So the villages on the frontier report, “Oh, we see this drone going in this direction at this time, and the next village does.” And then the girlfriends of all of the Air Force radar operators, their boyfriend says, “Incoming missiles.” And then they add that to the Telegram channel.

So you get this crowdsourced information that’s very accurate, actually, it turns out. Anyway, so we went then to the university and I get there at like seven and the universities have to operate now like 12 hours a day because the law requires that they have enough space for all classes to be moved underground in case of an air raid. And so they have had to lengthen their school day so that they can do that. And so I get there at eight o’clock, and the university is packed. Like, every surface has students, every hallway, every basement, every classroom, and they’re so hungry to learn. I mean, it just was really uplifting. Anyway, so that was my first day. And then the second day I was there, and there was an air raid during one of my lectures, and we had to relocate to this Soviet-era bomb shelter, like two stories underground with these blast doors.

Apparently it had been built because they were worried about a chemical attack from the Americans. And so there were these, you know the big circle thing you turn, like you see on submarines. And then I went into this bomb shelter to give my lecture, and the students were beaming. And I think they were happy because this foreigner, this American professor was there to witness their predicament. Witness... And so for me, it felt like a small act of solidarity. It was something practical I could do, very small, to help, to help communicate to them that you’re not alone in the world. You are the victims of this outrageous authoritarian assault, and I see you. I see what you’re going through. Anyway, that’s a little bit of the experience. And as you said, there is a video about it on the For the Love of Science channel with more details.

Harlan Krumholz: Do you ever reflect on legacy? What do you hope your legacy will be? I mean, what will it be that you will have left from the work that you’ve done?

Nicholas Christakis: I think that we are, all of us, the three of us, very grateful or very lucky, rather, to be in professions such as medicine and science that provide meaning to our lives. We have the opportunity to do work that offers great meaning. I think that if you’re a scientist, and I have a video about this, you join a conversation that stretches back centuries and that will outlast you for centuries. And if you’re lucky, you add a little stitch or if you’re lucky you add a whole line, or if you’re Newton or Darwin, you add a whole patch to this fabric. And so I just feel very fortunate that I was born into a century and into a place where there was an opportunity for me to have this life as a scientist and to benefit from all of the contributions of previous people. And I’m not saying this in a kind of Pollyannish way. It’s true.

When I was born, calculus had already been invented. It was just given to me when I was in high school. I didn’t have to invent that, and computers had already been invented and all of these tools that I use to do my work, other people invented and I just got to use them. And then I make my contributions and in the future someone else, Inshallah, will use those contributions. I think one of the things that’s very humbling is you read books by people written 100 years ago by scientists, social scientists and others who are forgotten and yet who are just brilliant. And so you realize that that’s your fate too, that you’re going to make these contributions and that’s it.

But while I’m alive, I’m finding it rewarding and makes me feel like I’m doing something helpful, which in some ways like you guys, I have taken care of patients in addition to doing research. I think in the end, although I derived a lot of satisfaction for caring for patients in my life, I think in the end, my contribution will have been bigger from the science that I’ve done than from the however many hundred or thousands of patients I cared for. Some people care for tens of thousands or hundreds of thousands of patients in their lives, but I’m not in that category.

Harlan Krumholz: And the students you’ve taught, and the—

Nicholas Christakis: The students, yeah, the students also... I mean, that’s much more... a common, you know, that’s an experience which... teaching others is an experience that every human being can have, but making scientific discoveries or healing others is a less common experience.

Howard Forman: Yeah. And look, you’ve had an enormous impact on specific students as well. We have one of your former students coming to do radiology here this July, Marcus Alexander.

Harlan Krumholz: I guess that was a failure. I guess that was...

Howard Forman: No, no, no, no. I mean, but the point is, there are so many people over the decades—

Harlan Krumholz: Just kidding, Howie.

Howard Forman: I know, I know. So many decades of amazing students that you have mentored and that still speak with reverence for you. So we appreciate you so much and grateful to have you at Yale and to have you joining us for a second time.

Harlan Krumholz: Thanks for joining us. Great to see you.

Nicholas Christakis: Thank you, guys, for having me and thank you for this podcast. I mean, this is also, I mean, “health and veritas,” those are very important values, health and truth and this podcast also is contributing to advancing the public understanding of science, which is hugely important.

Howard Forman: We sure hope so.

Nicholas Christakis: Especially now.

Howard Forman: We hope so. Thank you.

Nicholas Christakis: Thank you, guys.

Harlan Krumholz: All right. Well, as expected, Nicholas is just amazing.

Howard Forman: He’s brilliant. People describe him as a public intellectual, and he is the perfect persona of a public intellectual. He’s an expert and a scientist in one sphere, but he just knows about everything.

Harlan Krumholz: He does. He’s an extraordinary person, but I know another extraordinary person. His name’s Howie Forman, and he’s got something to say this week that I want to hear. So what’s on your mind?

Howard Forman: Yeah. So just for our listeners, we are recording this a few days early, but even today, Monday, we have some real good data on the Ebola outbreak, and I think people need to hear this. Since mid-May, nearly a thousand suspected cases have been recorded across an area of Democratic Republic of Congo. That’s an area larger than the state of Florida, spreading through three provinces and then also crossing into Uganda and reaching cities with international airports. Two hundred people are already confirmed dead, and those numbers are almost certainly undercounts. What makes this outbreak difference starts with the strain. This is the Bundibugyo ebolavirus virus rather than the Ebola viruses that we had seen in previous outbreaks. And critically, there is no approved vaccine, no approved treatment. What patients receive is supportive care, IV fluids, electrolytes, oxygen. In a world-class facility, that can save lives. In an overwhelmed field hospital in a conflict zone, it often cannot.

The disease begins like the flu—fever, headache, muscle pain but progresses rapidly to vomiting, severe hemorrhage, and circulatory collapse. It spreads through direct contact with the bodily fluids of someone who is sick. Crucially, it does not spread before symptoms appear, but here’s what most people don’t know. The body remains infectious for up to three days after death at peak viral load. In this outbreak, a single cracked coffin on a dirt road appears to have seeded a town of over 300 cases. Compounding everything, two of the three affected provinces are controlled not by the Congolese government, but by M23, a Rwandan-backed armed militia running a parallel administration. Running contact tracing and treatment centers in rebel-held territory is not a medical challenge, it’s a political one. One American is currently hospitalized in Berlin from this. He’s a physician. No cases have been reported in the United States, but this outbreak is already the largest of its strain in recorded history, and it’s just 10 days old as we report.

Harlan Krumholz: What I heard was that one of the things that happened about this was the delay in the recognition and that this had really spread a lot farther than anyone had realized—

Howard Forman: That’s right.

Harlan Krumholz: Before it was really recognized as such and that was one of the other contrasts with before.

Howard Forman: Absolutely. Look, the American physician who’s now hospitalized in Berlin and in very serious condition, he got infected because he was operating on a patient who he did not know had Ebola virus. You’re wearing a gown but you’re not wearing the protective garments to protect you from Ebola. It was very easy for him to get Ebola that way because we weren’t detecting it.

Harlan Krumholz: So one thing I was thinking about was the infectivity of it. We talked about this a lot with COVID, and we were sort of contrasting how does this sit with measles being the prototypical, the thing spreads like wildfire and highly infectious. How do you think about this one?

Howard Forman: So you’re not going to get it from being on a bus with somebody. You’re not going to get it from being on an airplane or walking down the street with somebody. The two most significant ways this seems to be being transmitted is within households because you’re sharing sinks, you’re touching each other, maybe you’re sleeping together, all of that. And the other way is something that is not culturally connected to us in America typically, but it’s that in these countries, people after death are bathed by their family members and community members and cleaned in preparation for burial. And it is during this peak infectious period that the people who are preparing them for burial are becoming infected. And that’s just not something we relate to here, but it’s very common there. And when you talk to people, everybody knows that.

Harlan Krumholz: So I mean, it sounds to me, I mean, we haven’t seen anything being picked up by more casual contact.

Howard Forman: No, no, no.

Harlan Krumholz: Yeah.

Howard Forman: But again, if you don’t know, casual context relative, three Red Cross volunteers who went into Congo, Democratic Republic of Congo to take care of the crisis have already been infected and I believe all three died. So even knowing what they had to do, even donning and duffing PPE and doing all the right things, if you’re around highly infectious people and not taking every possible precaution, you can get infected and die from this. So once you’re dealing with someone who’s very, very sick, you have to be extremely careful.

Harlan Krumholz: And it’s really about these screening tests because they were giving false negatives all this time because they were looking for the wrong one, as you were talking about.

Howard Forman: Exactly. Exactly. You need to be able to test a lot.

Harlan Krumholz: It’s going to be, in the end, really trying to understand that. Yeah.

Howard Forman: You got to test a lot. You got to do contact tracing and you got to really explain to people why their burial practices have to be curtailed during this time and why they have to be that much more careful. And it will get under control. It probably will turn out to be the second or third worst outbreak of Ebola in the continent. It could potentially go on to be the worst, but let’s hope not. The only good thing I could say is this is less lethal than the other versions of Ebola. About 30%, 35% die.

Harlan Krumholz: Yeah. And the only other thing I’ll say is that the whole world stands up and takes notice, but on any given week, hypertension takes more lives than Ebola.

Howard Forman: Absolutely. I mean, but this is so preventable and so immediately preventable that we need to do more, and let’s just not leave it on the table. We have withdrawn funding from these countries that would have otherwise helped. We have withdrawn funding from the World Health Organization, that would have helped. There are things, we don’t know how much they would have helped, but these were the connections and the tying together the, what do you call it? The connective tissue that helps us during these outbreaks.

Harlan Krumholz: Yeah. Even just being, yeah, all the surveillance work, all of that has been damaged. Yeah.

Howard Forman: Yes.

Harlan Krumholz: Well, thanks, Howie. Thanks for bringing it up. You’ve been listening to Health & Veritas with Harlan Krumholz and Howie Forman.

Howard Forman: So how did we do? To give us your feedback or to keep the conversation going, email us at health.veritas@yale.edu or follow us on LinkedIn or any of the social media. Also, you can watch our latest Howie and Harlan episode on YouTube. You can find last week’s episode on the Yale Insights YouTube channel.

Harlan Krumholz: And that’s a good opportunity for you to give us feedback. What do you think about it? We thought posting that might be a good idea, and yeah, give us feedback on anything. We always want to make the podcast better.

Howard Forman: Absolutely. Health & Veritas is produced with the Yale School of Management and the Yale School of Public Health. To learn about Yale SOM’s MBA for Executives program, visit som.yale.edu/emba, and to learn about the Yale School of Public Health’s Executive Master of Public Health program, visit sph.yale.edu/emph.

Harlan Krumholz: And a hat tip to our superstar undergrads, Donovan Brown, Gloria Beck; to our fantastic producer, Miranda Shafer. And I’ll just say I’m going to China this week, so we had to tape this on Memorial Day. Kudos to those two, Donovan and Miranda, for supporting us on a holiday.

Howard Forman: Absolutely. Yes.

Harlan Krumholz: And I want to thank Howie, the best in the business, and thanks so much for showing up today, Howie, and for being as good as you are.

Howard Forman: Thank you, Harlan. Have a great, safe trip. Talk to you soon.

Harlan Krumholz: Thank you. Talk to you soon.