Wednesday, March 7, 2018

Did Dogs Become Smarter Through Domestication? An Interview with Dr. Brian Hare

by Felipe Nogueira

Dr. Brian Hare is an associate professor in the Department of Evolutionary Anthropology at Duke University and in the Center for Cognitive Neuroscience. Hare is a pioneer and a key expert in the field of dog psychology. Together with Vanessa Woods, Brian Hare has written about the revolution in the study of dog cognition in the fascinating book The Genius of Dogs: How Dogs Are Smarter Than You Think. The book, in their own words, is “about how cognitive science has come to understand the genius of dogs through experimental games using nothing much more high-tech than toys, cups, balls, and anything else lying around the garage.”
Hare and other researchers showed many times that dogs are good at understanding humans’ communicative intentions. With the help of a brilliant experiment with foxes begun by Dmitri Belyaev in the 1950s and continuing to the present day, Hare’s research uncovered what allowed dogs to develop this remarkable skill: domestication After 45 generations, Belyaev’s foxes in the experimental group had floppy ears, curled tails, and were much better reading human gestures than the foxes in the control group. The key point is that Belyaev didn’t select for foxes better at reading human gestures; instead he selected for foxes less afraid and friendlier towards humans. As Hare and Woods note in their book: “Domestication, selecting the friendliest foxes for breeding, had caused cognitive evolution.”
In order to understand even more the limitations and flexibility of canine cognition, researchers have created dedicated laboratories, such the Duke Canine Cognition Center, created by Hare. 

Dr. Brian Hare
Nogueira: In your book, you talked about the genius of dogs. But what do you mean by being a genius?
Hare: If you’re talking about high IQ, or who is going to be recruited to work for NASA, that would make a very short book. In my opinion, the big discovery in the cognition revolution is that cognition it’s not a unique dimensional trait. Actually, it’s a whole set of skills that can vary independently and we don’t know how many there are. For instance, one can be great at math, but a terrible communicator. Regarding species, each one evolved to solve a set of problems that helped them survive and reproduce in their particular environment; dogs are no different. My book The Genius of Dogs is all about trying to understand how a species that seems utterly unremarkable can can be so successful. Dogs are successful from an evolutionary perspective because, everywhere there are people, there are dogs. It’s the most successful mammal—aside from humans and maybe cows. That’s what the book explores: do dogs have some type of genius psychologically or cognitively? Yes, they show unusual degree of sophistication and flexibility for solving problems.

Nogueira: Tell us how you started researching dog cognition.
Hare: Michael Tomasello, a developmental psychologist and my research supervisor at the time, was explaining to me how important gesture communication is in human development. He thought it was not only crucial to human evolution but something unique to humans. His theory was that kids developed the ability to use human gestures and to understand communicative intention. Then I told him that my dog could do the same thing. That’s when I learned what science is, because even though it was an important idea for how humans evolved, Tomasello became curious. He said to me: “I will help you to come up with a way to prove me wrong.” That’s incredible! When he discovered that he was wrong about dogs, he was excited, telling us to keep doing more experiments. People think science is about people in lab coats coming up with genius ideas, but in reality it’s a way to falsify ideas.

Nogueira: How was the first experiment with dogs?
Hare: We use a powerful, but very simple technique: we hide food in one of two containers. Then we pointed to where we hide it, trying to help the dog search for it. Great-apes are terrible at this task. They don’t show much cognitive flexibility, since they have to learn the gesture. And every time you use a new gesture, they have to learn again. In contrast, in kids around age 12 months, you can use gestures they’ve never seen before, showing a degree of flexibility that it’s not seen in great apes. With dogs we performed the same series of experiments that had been done with apes and human children. The big surprise was that dogs are more like children.

            This was a controlled experiment: dogs were not using their noses nor reacting to motion. In science, there are two steps. First, you have to demonstrate a phenomenon. If it’s gravitational waves or dogs following gesture, you have to demonstrate the phenomenon. Then, you try to explain it. Often, people are so busy trying to explain something before they even demonstrate it exists. Once we demonstrated that dogs were following a pointing gesture, we wanted to know if they, for example, just smelled the hidden food. We found that wolves, dogs and foxes all preferred to use their eyes. When they can’t get the information they need from their eyes, then they use their nose. In these experiments, we found that dogs prioritize information from their eyes and memory over their nose.

Nogueira: One of the fascinating experiments with dogs you mentioned in the book uses an opaque barrier. Could you elaborate on it?
Hare: This is the work of Juliane Kaminsky, Michael Tomasello, and Josep Call. They have placed a ball behind two barriers, one opaque and one transparent. The dog can see both balls. In the experimental condition, a human, on the opposite side of the barriers, asks the dog to fetch the ball. The amazing thing is that dogs didn’t take the ball from the opaque barrier, which the human can’t see through; they favored the ball from the transparent barrier. In the control condition, where the human and the dog are on the same side, seeing the same thing, the dog choose the balls randomly. This experiment suggests that dogs know what humans can or cannot see.
Experiment conducted by Kaminski et al [2].
Nogueira: What are the possible explanations for why dogs are so good at reading human gestures?
Hare: One level of explanation is that, since dogs have seen these gestures several times, they slowly learned them. You can test this idea by using a gesture they’ve never seen before, for instance, point with your foot. You can also use a crazy gesture, like putting an object on top of the container where the food is located. Human children and dogs follow those gestures, but chimpanzees don’t. So, this hypothesis of slow learning was ruled out. But the hard part is this: how do you know if dogs really have a sophisticated flexible strategy, a theory of mind, which would mean that they’re thinking about the thought of others individuals?. The best evidence about other animals that have a theory of mind comes from great apes and maybe corvids. Regarding dogs, in fact, we don’t have the smoking-gun experiment to rule out alternative explanations. Then, we don’t have overwhelming evidence that dogs really have a theory of mind. For instance, the experiment with the opaque barrier, when the dog knows what people can or cannot see, hasn’t been replicated. Moreover, when you are studying something like a theory of mind, you want multiple experiments where an animal shows the same set of skills. We have that with great apes, but we don’t have with dogs yet.

Nogueira: From where do these remarkable skills of dogs come?
Hare: We tested several hypotheses. The first was that they were related to wolves, which are clever and maybe are also good at reading human gestures. The other was experience: they interacted with us and have slowly learned it. Finally, we considered if it’s something that happened during domestication. The evidence is mostly in favor of domestication: selection for friendliness is what allowed dogs to become more skilled at reading and using humans to solve problems. That was a surprise: why would being selected to be friendly make you smarter?

Nogueira: How has the Belyaev’ fox research helped to answer that question?
Hare: This brilliant experiment was conducted by a group of scientists in Siberia headed by Dmitri Belyaev. They have a control and experimental line of foxes, separated from each other. The control line was bred randomly. In the experimental line, Belyaev selected foxes that were attracted to or enjoyed interacting with people and weren’t fearful. In other words, Belyaev selected friendly foxes and let them breed together. Over many generations, the experimental foxes show a high frequency of traits that Belyaev didn’t select for, such as floppy ears, curly tails, and multi-color coats. The foxes also had physiological changes related to reduction in aggression and increased friendliness. This experiment was important to our research because they have a population that was experimentally domesticated. This was a great opportunity to test the idea that if domestication really is selection against aggression and for friendliness for people. It makes sense: how can you have a domesticated animal if it just wants to attack you or is too scared to come near you? The foxes also led us to questions about psychology: Is this remarkable ability of reading human gestures and to use humans as social tools also a product of selection for friendliness? The answer is yes: the domesticated foxes acted like dogs regarding their ability to read human gestures while the control line did not; they behaved like wolves.

Nogueira: You mention in your book that, “without an experiment, we were slipping from science into the realm of storytelling.” Could you elaborate why we need experiments? 
Hare: We published a paper in Science ruling out the first two hypotheses.1 The first is that dogs’ remarkable skills of reading human gestures evolved in wolves and were inherited. Second: lots of experience gives dogs these skills. We didn’t find any evidence for these hypotheses, so by default we favored the domestication hypothesis. We didn’t have evidence for it; we only had evidence against the other two hypotheses. If Belyaev had not done his domestication experiment, we would have been stuck at that point. Belyaev’s work established the possibility of testing if domestication made dogs able to read human gestures. We did an experiment with the foxes and we were surprised: even though they were not selected to be smarter or to be better at using human gestures, they were as a result of being selected for friendliness. We had direct evidence that it was domestication that did it.2 People might think that we domesticated dogs and made them smarter, but it does not mean it’s true.

Nogueira: If it’s not true, what probably have happened?
 Hare: People tend to think we created dogs as our own image. The best evidence suggests that animals had an advantage if they were friendly to people; they will reproduce more. I was in a restaurant eating outside and there were sparrows stealing food in a few inches of my feet. Those sparrows are eating tons of food, they are fat and healthy. That’s because they’re not afraid of people. I think something like that happened with dogs. In some point of human evolution, humans created a new food resource that if you could be friendly enough and not fearful of human population you were a big-time evolutionary winner. So, a population of wolves chose us; we didn’t choose them. Since hunter-gathers competed with wolves, it does not make sense to bring animal like wolves close to your children. The wolves realized, just like the birds under my table realized, the wonderful resource is scraps around human camps. After a few generations, they would show morphological changes, like those we’ve seen in the foxes, so people could tell the difference between those and the other wolves we competed with. That would be a major selection advantage.

Nogueira: How evolution is related to those changes?
Hare: Selection against aggression and for friendliness toward people creates several changes beyond that in morphology and psychology. Once these new differences are there, selection can act on that too. The point is that these new changes were not created; humans did not think to create dogs with floppy ears, for example. Some individuals had floppy ears because selection against aggression. Then people could breed these individuals to make more floppy ears. In other words, we took the advantage of the variance created by the selection against aggression. Evolution is not any different to gravity. If I drop a ball, I can’t stop it from dropping; it’s unstoppable force. Evolution is also unstoppable. Just because you can’t see, it does not mean it’s not acting all the time. Another example is that there is a white deer that comes to eat in my front yard. Normally, deer coming near humans is a bad idea. If you live in hundred yards from my house, a deer in your front yard would soon be dinner. But where I live in the suburbs everybody think deer are cute and adorable. Where I live, there is higher proportion of deer with different color coats; there are more white and albino deer. Research already shows that deer that are invading urban areas are larger, more social and have more offspring than deer living far away from humans.*

Nogueira: This process of domestication that happened with dogs probably have happened with other animals well, which we called convergence of evolution. What do we find, for example, when we compare chimpanzees and bonobos behavior regarding aggression, attitudes towards strangers and so on?
Hare: Bonobos served as a test-case for the hypothesis that natural selection, and not artificial selection, caused domestication. We called it self-domestication: species, through natural selection interfacing with its environment, end up like a domesticated animal. When we compare chimpanzees and bonobos to wolves and dogs, many changes between wolves and dogs were found between chimpanzees and bonobos. Chimpanzees are like the wolf of the ape family. Weather we’re talking about morphological or behavior characteristics, bonobos are really the dog of the Ape family.

Nogueira: At Skeptic, we advocate for evidence-base thinking. Since you had communicated with the public, what do you think is the best approach to shift people from faith-based thinking to evidence-based thinking, increasing, for example, the acceptance of evolution?
Hare: In US, people think that Christians have a problem with evolution, but the Catholic Church says evolution is consistent with Catholic doctrine. People love to play the “in and out” group card: science is something that other people do. If one is religious and faithful, one can’t believe in science, since science is anti-religion. That’s the typical in-out group response. People use strategies to target science, or evolutionary thinking, as the out group. As someone who studies evolution, the first thing is to notice that humans evolved to see in-out group everywhere. If you say something like “you’re religious and you’re not like me”, it’s over. As a science communicator, I’m going to say that Catholic Church has no problem with my research in order to turn-off the in-group out-group response. The entire intent of my book The Genius of Dogs is to get people who had never read about evolution and cognitive science excited to read about it, because they care about dogs. Darwin intentionally started The Origins of Species with a chapter about domestication, because he knew people were familiar with and were not threaten by it. I think we have to do the same thing.

Nogueira: Thank you for this amazing interview and keep up the fascinating research!

1.    Hare B, Tomasello M. 2005. Human-like social skills in dogs? Trends in Cognitive Sciences 9: 439–444.  
2.    Kaminski J, Bräuer J, Call J, Tomasello M. 2009. Domestic dogs are sensitive to a human’s perspective. Behaviour 146: 979-998 pdf/Kaminski_et_al_2009a_dogs_sensitive_humans _perspective.pdf.
3.    Hare, B Hare, B., Homo sapiens Evolved via Selection for Prosociality. Annu Rev Psychol. 68:155-186:
4.    Hare B., M. Brown, C. Williamson, and M. Tomasello. 2002. “The domestication of social cognition in dogs.” Science. 298: 1634-6.
5.    Hare B., et al. 2005. “Social cognitive evolution in captive foxes is a correlated by-product of experimental domestication.” Current Biology. 15: 226-30.

* Here I corrected a minor mistake that was published in the original version at the magazine. I also corrected Figure 2's subtitle: the correct reference number is 2 (Kaminski et al, 2009). 

Friday, February 2, 2018

Reflections on Sean Carroll’s The Big Picture

by Felipe Nogueira

Sean Carroll is a theoretical physicist at the California Institute of Technologies. He has also dedicated a considerable amount of time to science popularization through his books, such as From Eternity to Here and The Particle at the End of the Universe, and debates, for example with theologian William Lane Craig.

Carroll’s latest book is The Big Picture: On the Origins of Life, Meaning and the Universe Itself. Published by Dutton, the book came out in May 2016. With that title, it’s right to assume that Carroll covered many topics in the book. A look at the table of contents finds six parts, with topics such as “The Funda­mental Nature of Real­ity,” “Interpreting Quan­­tum Mechanics,” and “The Origin and Pur­pose of Life.” But in short, the book is about poetic naturalism.

Naturalism asserts, as Carroll puts it, that “there is only one world, the natural world, exhibiting patterns we call “the laws of nature,” which are “discoverable by the methods of science and empirical investigation.” He makes it crystal clear that within naturalism there is no space for the supernatural: “There is no separate realm of the supernatural, spiritual, or divine; nor is there any cosmic teleology or transcendent purpose inherent in the nature of the universe or in human life.”

And what is the natural world made of? Our deepest understanding of reality, or in other words, our fundamental ontology is The Core Theory, a better term coined by physicist Nobel Prize winner Frank Wilczek for the Standard Model of particle physics. “It’s the quantum field theory of the quarks, electrons, neutrinos, all the families of fermions, electromagnetism, gravity, the nuclear forces, and the Higgs,” Carroll explains. So on our most fundamental level we have a sparse ontology, containing several different entities.

The Core Theory also 
tells us something very im­portant about the world: there is no such thing as astrology and life after death. Carroll had written about this on his blog [1], and he repeats this spectacular argument again in the book. Using our fundamental ontology, the world, including our bodies, is made of particles interacting according to equations of the Core Theory. The important point here is what kind of particles is the soul made of? If souls are made of the same ordinary particles as human bodies, there is no afterlife. On the other hand, if they are made of a different particle, this certainly would require a new physics to describe the interaction between our bodies—collections of ordinary Core Theory particles—with the soul. But every experiment ever performed says the Core Theory provides the correct description of how its particles behave at everyday energies. We know it’s not a complete description of everything that exists in the world—for example, dark matter is not included in it—but it describes everything related to human beings. If it exists, an immaterial soul that interacts with our bodies would prove the Core Theory is not right at everyday energies; the Core Theory would then need to be modified to include how its particles interact with the soul. One cannot believe in the existence of the soul and also believe the Core Theory is the correct description of how particles behave at everyday energies. “There is no life after death. We each have a finite time as living creatures, and when it’s over, it’s over.” Carroll blows the hope for the soul away.

The same line of reasoning can be applied to astrology. The Core Theory particles make human beings interact with a few forces of nature: gravity, electromagnetism, and strong and weak nuclear forces. But the nuclear forces do not reach macroscopic scales, and gravity is too weak—gravitational force from other planets might be equivalent or even weaker than that of a person nearby. We’re left with electromagnetism, but it’s not difficult to think that any electromagnetic signal coming from other planets will be interfered with signals originated here on Earth.

This brings another important question: What about things that are not part of the Core Theory? Are they just illusions? No! These can be useful ideas to describe real phenomena that manifest at higher scales. Temperature and entropy, for example, are not part of our fundamental ontology, but they’re real; they are emergent phenomena.

This is why Carroll is a poetic naturalist, and he does a great job throughout the book of differentiating fundamental from emergent phenomena, highlighting that both are real. But poetic naturalism is bigger than that; it has space from moral values, even if they’re part of our deepest ontology and not emergent. For Carroll (although Sam Harris certainly disagrees [2]), morality is not something out there to be found and cannot be discovered by science, but it is not less important. Poetic naturalism embraces all these “views” together. In Carroll’s own words:

Within poetic naturalism we can distinguish among three different kinds of stories we can tell about the world. There is the deepest, most fundamental description we can imagine—the whole universe, exactly described in every microscopic detail. Modern science doesn’t know what that description actually is right now, but we presume that there at least is such an underlying reality. Then there are “emergent” or “effective” descriptions, valid within some limited domain. That’s where we talk about ships and people, macroscopic collections of stuff that we group into individual entities as part of this higher level vocabulary. Finally, there are values: concepts of right and wrong, purpose and duty, or beauty and ugliness. Unlike higher level scientific descriptions, these are not determined by the scientific goal of fitting the data. We have other goals: we want to be good people, get along with others, and find meaning in our lives. Figuring out the best way to talk about the world is an important part of working toward those goals.
To conclude, it’s a great book, covering a wide range of interesting topics. In fact, it’s impossible to fairly account for all the good stuff in the book in a short review like this. Go read it!



Thursday, February 1, 2018

The discovery of gravitational waves. An interview with Lawrence Krauss

by Felipe Nogueira
published in Skeptical Briefs Volume 26.2, Summer 2016

On my previous column, I briefly covered the fascinating discovery of gravitational waves. For this this column, I had the opportunity to talk about it with Lawrence Krauss, a theoretical physicist and cosmologist at Arizona State University (ASU) and author of A Universe from Nothing.  

Nogueira: Can you explain briefly gravitational waves and general relativity? 
Krauss: General relativity is a theory of space and time. Einstein showed that matter affects the properties of space and time around it; space curves, expands, and contracts because of matter. A massive body affects the space around him and, when it moves, the massive body produces a disturbance of the space that can propagate out, like a ripple when you throw a stone in the water. In 1916, Einstein showed that such disturbance would propagate out and would be a wave, a gravitational wave. Just like electromagnetic waves happen when you jiggle a charge, a gravitational wave is a disturbance of space. That means the properties of space changes when a gravitational wave goes by. If there are gravitational waves in this room right now, the distance between my hands would be smaller, but my length would be longer, then in instants later, this changes: my length would contract and the distance between my hands would be longer, and so on. Einstein thought that gravitational waves would never be observed. He also retracted gravitational waves later on 1937, when he tried to solve the equations of gravitational waves and came up with an answer that didn’t make sense. He submitted the paper to Physical Review and it was rejected. He got upset, since he had never been peer-reviewed before. He said that he had sent the paper to be published, not to be reviewed. But it served him well, because before he could submit elsewhere, he and someone else realized the mistake in the paper and the final published version is correct. Thus, for a brief time, Einstein though gravitational waves didn't exist.

NogueiraEinstein also changed his mind about the cosmological constant, didn't he?
Krauss: He introduced the cosmological constant, because he thought the universe was static and he thought the cosmological constant would make the universe static. In fact, he was wrong on both grounds. The universe is not static and because of that Einstein said it was a big blunder to have the cosmological constant included. But it was a big blunder anyway, because a cosmological constant does not result in a static universe. It generally results a universe we live in now, which is exponentially expanding.

NogueiraAbout five years ago, we discovered the Higgs Boson. It was a major discovery as it's this discovery of gravitational waves. I have the impression that there was more excitement with this current discovery than with Higgs Boson. Is this impression correct? 
Krauss: I think it got more advance notice and I am partly responsible for that. But everything related to Einstein somehow capture the public imagination. Einstein predicted gravitational waves 100 years ago and Higgs predicted the Higgs' particle 50 years ago. The real difference is that the discovery of the Higgs boson is a major discovery of something very important in the Standard Model, but it doesn't guarantee that will be more discoveries or that would open up new windows beyond that. The discovery of gravitational waves was something like the telescope was just turned on: it was the first time that we had a machine that could do this, and we're pretty well certain that we will be able to use this over the next century as a probe of the universe. It's quite possible the machine that discovered the Higgs reveals to us more, but it's no guarantee. In contrast,  knowing that we have gravitational waves, it tell us that we will be able to see a lot more about the universe than we saw before.

NogueiraWhat kind of ideas might be tested using gravitational waves?
Krauss: We never measured general relativity in a strong regime near an event horizon, where space is highly curved. We never measured strong gravity gravity has always been week.  With these results, it looks like general relativity applies in those domains. So, we can extrapolate it to domains where space is curved and rolling like a boiling sea, and not as gentle ripples. This will be a good test of general relativity. As we probe the physics close to the event horizon, we'll learn the nature of black holes.  And who knows what else we'll learn? Every time we opened up a new window in the universe, we were surprised. So, I'll be surprised, if we are not surprised.

NogueiraA story circulated in Brazilian newspaper saying that this discovery would make time travel possible in 100 years. Time travel was also addressed by Kip Thorne at LIGO’s press conference. What can you comment about it?
Krauss: It has nothing to do with time travel. It means that we can explore general relativity in a regime where gravity is very strong and fields are very massive. But it doesn't tell us that we will be able to do time travel in any way; who said that doesn’t know what they're talking about. Kip Thorne was in an event called Einstein Legacy at ASU, which can be seen online [1]. Thorne made it clear he doesn't think time travel is possible, even though he spent time writing papers to see if it was possible.

NogueiraRegarding the non-scientist population, how can this discovery have an impact or to be relevant for them? 
Krauss: These two black-holes collided in a second and they emitted an energy equivalent three times the mass of the sum. This is more than the energy emitted by all the stars in the visible universe during that moment. Those kinds of things can amaze you. As I say, it tells us a little bit of what we came from and where we are going; it enhances our place in the universe. So, from a cultural perspective, it's part of the beauty of being human. It's not going to produce a better toaster, but the technology used on the experiment could be used on other things.

NogueiraHow LIGO experiment was done?
Krauss: The experiment is amazing. In order to detect gravitational waves, there are two arms perpendicular from each other in a detector. If a gravitational wave comes by, one arm will be shorter and the other will be longer, alternatively. To measure the length, a laser beam is emitted and travels until it reaches the end of the arm, then it bounces back. This is done in both arms. If one arm is shorter, the laser will take less time to travel it than in the other arm. That sounds easy, but they have to able to design a detector that can measure the difference in length between two four-kilometer long tunnels by a distance of one ten-thousandth the size of a proton. It's so small the quantum mechanical vibrations of the atoms in the mirror they used are much bigger than that. It's like measuring the distance between here and the nearest star with accuracy of the width of a human hair. It's an amazing bit of ingenuity, perseverance and technology; it's really beautiful!          

NogueiraIs this the last prediction to be discovered regarding general relativity? Even such, we know it's not the final answer. Why is that the case? 
Krauss: Gravitational waves were the last aspect of general relativity that needed to be tested directly; it's completely right.  And so is quantum mechanics; it has been tested so much that it's a fundamental theory. But we know that quantum mechanics and gravity don't work together. In very small scales, where quantum mechanics ideas are important and gravity is strong, the two don't go together; we know something has to give.    

NogueiraFor you, what would be the next most exciting discovery in physics? 
Krauss: The waves that have been seen are interesting, but for me it's much more interesting waves from the earliest moments of the Big Bang during inflation. We thought we had discovery it in the last year. We can look for their signature in cosmic background radiation coming from the big bang. If we can detect their signature, we will be able to probe the physics of the very early universe - the nature of quantum gravity itself. LIGO's detector is not sensitive to those waves from the big bang, but we might build big detectors in space that could be sensitive. I’ve written a paper with Nobel-prize winner Franck Wilczek showing that if you can measure gravitational waves from the Big Bang, they will prove gravitational waves is a quantum theory.  

NogueiraI know you have an upcoming book. What can you comment about it?
Krauss: It's called The Greatest Story Ever Told So Far and will come out probably on March 2017*. It's the story about the greatest intellectual journey humanity has ever taken, all the way from Plato to the Higgs. My last book discussed the question "why is there something rather than nothing" and this new one address the question "why we are here?" The new book was built up on a lecture with the same title, which is also available online [2], but of course there is a lot more on the book than in the lecture. The book also talked about the future based what we know with the discovery of the Higgs.   

[1] Einstein's Legacy, Celebrating 100 Years of General Relativity: An Origins Project Panel.

* Update: the book has been published. My review of the book was also published at Skeptical Briefs. 

Monday, January 1, 2018

Reflections of a A Scientist in Wonderland

published in Skeptical Briefs volume 25 number, Summer 2016.
by Felipe Nogueira

Edzard Ernst is a medical doctor and the worlds first professor of alternative medicine. I always thought that his story is quite interesting. For years, Ernst has been a strong skeptical and critical voice of the often extraordinary claims done by alternative medicine proponents. In his blog he posts in a daily basis critical analysis of alternative medicine studies. In his 2008 book Trick or Treatment, co-authored with Simon Singh, Ernst had explained the history and evidence about different alternative medicine therapies, from acupuncture to homeopathy to chiropractic. However, this skeptical scientist had started his medical career as a homeopath. How that happened? How did he change his mind?  

The answers to those questions and other interesting details of Ernsts career are written in his latest and excellent book. A Scientist in Wonderland was published in January and is a memoir of searching for the truth and finding trouble, as the subtitle says.

Ernst went to medical school in Germany. I was amazed to know that he actually wanted to be a musician, rather than a doctor. Even after he finished medical school he recognized this passion: "I still felt much more like a musician than a doctor". Around 1970, Ernst had difficulties when he was looking for a job as junior doctor, but he found in the only homeopathic hospital in Germany.

He worked in different places in Germany, including in the University of Munich, but it was in London that he had his first job as researcher, in a blood rheology laboratory at St George's Hospital. For the first time, he felt in the right job, because he was working with several intelligent people, going to conferences and publishing papers. Medical school was focused on clinical medicine; he didn't learn to be a scientist there. Working in that laboratory, he begun to realize that science of medicine was really important. With enough time to think, read, and learn, for the first time he questioned clinicians' most basic assumption that if a patient feels better, the cause is the treatment. Differently, a medical scientist is trained to be skeptical, to doubt, and to question this kind of assumption. In Ernst's own words, "An uncritical scientist is a contradiction in terms: if you meet one, chances are that you have encountered a charlatan. By contrast, a critical clinician is a true rarity, in my experience. If you meet one, chances are that you have found a good and responsible doctor".

The job as a researcher was good, but Ernst missed clinical activities. He changed jobs a couple of times, until he found a place where he could do research and clinical activities, in Munich. The research was so productive that he achieved a PhD without difficulties. At that time, around 1981, he published his first paper on alternative medicine.
It was in 1992 that his life was about to change dramatically as he saw an advertisement of the chair of complementary medicine at the University of Exeter. After one year, he was nominated for that task.  The mission of his research team was to conduct rigorous research into the efficacy, safety and cost of complementary medicine. However, as one can expect, alternative therapists don't want that. Enrst wrote, "Some offered the opinion that alternative medicine should not be scientifically scrutinized at all."

Ernst promised he would investigate the most popular alternative therapies in UK. For his surprise - and to my own as I read the book - spiritual healing was a common alternative therapy. At that time, there were more healers than chiropractors, osteopaths, acupuncturists, homeopaths and herbalists combined and almost the same number of mainstream physicians. Ernst and the healers agreed with the experimental methods to be used and the trial would test healers efficacy for chronic pain.

A Scientist in Wonderland explains why the best way to evaluate the efficacy of treatments is through a randomized controlled trial. In this kind of experiment, participants are separate randomly at least in two groups: the intervention group (the therapy to be tested) and the control group. If the therapy to be tested is a drug, the control group is given a pill that doesn't have any effect, a placebo. However, when a non-drug therapy is being tested, the "placebo" isn't that straightforward. We can't simply do nothing in the control group, patients need to be given something that looks like the therapy being tested but with no effects. Thus, when the trial is done, scientists use statistics in order to compare the difference between the groups. "Any effective treatment - effective beyond placebo that is - will generate a specific effect plus a placebo effect", Ernst explains.  

The spiritual healing trial ended up with four groups: healing by one spiritual healer; placebo-healing by a trained actor; healing by a healer in a cubicle hidden from the patient's view; and, placebo-healing with no human present in the cubicle. During the study, Ernst witnessed a pain relief so intense that one of the patients stopped using his wheelchair. Remarkably, the pain reduction was due to placebo effect, since the results showed that all groups have considerable pain reduction with no statistically significant difference between them. Ernst and his colleagues published the paper trial with a clear conclusion: "a specific effect of face-to-face or distant healing on chronic pain could not be demonstrated".

Readers will also learn in Ernst book that the importance to investigate alternative treatment is not only to know if it works or not, but also to know if it's safe or not. The patient might be harmed by the treatment directly, which can happen, for example, with acupuncture when the therapist causes a pneumothorax. Every treatment has its risks, even homeopathy that has no active substance in its pill. Why? Because patients might seek a not established treatments rather than an effective one. Moreover, one of Ernst' research showed that half of homeopaths would recommend against MMR vaccine. Thus, alternative therapists might produce considerable harms and we must not neglect that. 

Ernst has received several awards due to the quality of his research. However, for alternative medicine proponents, quality of research is not important. What is important is to defend alternative medicine, even in the absence of evidence. Speaking out the truth about the available evidence, Ernst criticized statements from alternative medicine promoters, such as the famous Prince Charles. At the time, the Dean of Exeter University questioned Ernst: do you always have to be undiplomatic? It certainly appears, for this question alone, that the Dean is more worried with being political rather concerned with the truth and possible harms of alternative medicine. What if the evidence from alternative medicine research is undiplomatic itself? It turns out to be case, as Ernst put it, our critical analyses of alternative medicine, once acclaimed locally, nationally and internationally, seemed no longer wanted.

What about ethics? Ernst doesnt let anyone forget that this is critically important in medicine. Doctors occupy a position with authority and power, and patients are vulnerable and often theyre suffering. Ernst is brilliant as he wrote: 
when science is abused, hijacked or distorted in order to serve political or ideological belief systems, ethical standards will inevitably slip. The resulting pseudoscience is a deceit perpetrated on the weak and the vulnerable. We owe it to ourselves, and to those who come after us, to stand up for the truth, no matter how much trouble this might bring.
In fact, the fight with Prince Charles generated much trouble. Despite the fact that Ernst and his team had published more papers in peer-review medical literature than the rest of the Exeter University together, disagreements with Prince Charles culminated with Ernsts team being isolated and with no funding. Eventually, the situation became so terrible that the team was disbanded and Ernst had to take retirement. He wrote, The doctor and scientist may still be full of questions, but the musician in me breathes a sigh of relief that the performance, with all its impossible demands and fiendishly difficult passages, is finally over.

Ernst closes the book with a brief summary of the most important conclusions from his research regarding the efficacy of acupuncture, chiropractic, herbal medicine, and homeopathy. A Scientist in Wonderland must be given to anyone that promotes alternative medicine. The book mentions important principles regarding treatments evaluations. The book shows the amount of trouble a team of scientists can face when their research findings contradicts beliefs and opinions of people with power. Moreover, it shows the importance of the truth.

Id like to thank Edzard Ernst for having written this fascinating book about his career, but also for having the courage to stand up for the truth and for being the example of a scientist we need in all fields, especially in alternative medicine. Ernst is, as Harriet Hall has said in her review of the book on the Science-Based Medicine blog, a true hero. He continues to be one of our leading warriors in the battle to defend science and conquer unreason. 

Thursday, May 5, 2016

Medical error - the third leading cause of death in the US

by Felipe Nogueira

Published two days on the British Medical Jorunal, study estimates that medical error is the third leading cause of death on US.

Most common causes of deaths in the United States in 2013:

1 - Heart disease: 611k
2 - Cancer: 585k
3 - Medical error: 251k
4 - COPD: 149k
5 - Suicide: 149k
6 - Firearms: 34k
7 - Motor vehicles: 34k

2013 Causes of death in the US. Source: BMJ [1]

It gets worst: according the authors,  medical error is not registered on US death certificates.

The  authors conclude that "the system for measuring national vital statistics should be revised to facilitate better understanding of deaths due to medical care" [1].

[1] Makary MA, Daniel M. Medical error-the third leading cause of death in the US. BMJ 2016;353;i2139.

Monday, November 9, 2015

Where Drugs Myths Die. An Interview with Dr. Carl Hart

Published in Skeptic Volume 20 number 2 
(article translated to portuguese on link)

By Felipe Nogueira
Interview with Hart: cover story on Skeptic
Carl Hart is an associate professor in the departments of Psychology and Psychiatry at Columbia University, and a research scientist in the Division of Substance Abuse at the New York State Psychiatric Institute. He is a member of the National Advisory Council on Drug Abuse and on the board of directors of the College on Problems of Drug Dependence and the Drug Policy Alliance. After receiving his B.S. in psychology at the University of Maryland and his Ph.D. in experimental psychology and neuroscience at the University of Wyoming, he went on to publish many papers in prestigious scientific journals for which he was made a Fellow by the American Psychological Association. In 2012 he co-authored with Charles Ksir the highly regarded textbook Drugs, Society, and Human Behavior (McGraw-Hill).

As a neuropsychopharmacologist Dr. Hart researches the effects of drugs on human physiology and behavior. For example, one of his experimental objectives was to understand how crack cocaine users would respond when given a choice between the drug and another appealing option—money. Contrary to what most people would think, Hart’s experiment revealed that drugs users can behave rationally, choosing other appealing options than destructive drugs. Thus, the medical model of addiction that treats it like a disease is not fully accurate when compared with, say, AIDS or cancer, which patients cannot simply choose not to have. Many people do quit drug use, even addicts. The question is, why?

Being a distinguished drug scientist is only part of Hart’s fascinating personal history with drugs. He was raised in a poor neighborhood in Miami where in high school he not only used drugs but also sold marijuana, and in the process committed petty crimes. To make matters worse, most of his relatives didn’t recognize the value of a formal education, so he ended up joining the United States Air Force, which gave him a deeper appreciation of the importance of knowledge, especially scientific knowledge and the ability to think critically, eventually leading him to become the first African-American tenured science professor at Columbia University.  

In 2013, he published High Price: A Neuroscientist’s Journey of Self-Discovery that Challenges Everything You Know About Drugs and Society (Harper), a book about research, myths, laws and public policy about drugs written for a general audience. The book is also a memoir, where Hart discusses his personal life and how he turned out to be the scientist he is now. High Price received the 2014 PEN E.O. Wilson Literary Science Writing Award, and he has since appeared as a regular guest on talk shows such as Bill Maher’s Real Time on HBO, where on the September 27, 2013 show the host made his usual plea for the legalization of marijuana, to which Dr. Hart added that cocaine, heroine, and methamphetamines should also be decriminalized so that people can get the help they need and we can empty out our prisons of such victimless crimes. He schooled Bill O’Reilly on the facts about addiction (texting doesn’t count), pointed out to him that the last three presidents of the United States smoked pot in their youth, and that, in fact, marijuana use among high school kids has declined from 37% in 1978 to 22% today (O’Reilly insisted it was higher, to which Dr. Hart responded bluntly “you’re wrong”).

In this sense Carl Hart is the mythbuster of drugs, the debunker of addiction myths, and a true skeptic of the pseudoscience and nonsense underlying this country’s attitudes about drugs and drug addicts.

Skeptic: Many people believe marijuana is a gateway drug. Is it?
Hart: It all depends what is meant by “gateway drug”. What people often mean is that marijuana leads to hard drugs. That is not true. It is true that the vast majority of people who use heroin and cocaine, for example, used marijuana before they used these hard drugs. But, then you look at the fact that the vast majority of marijuana smokers don’t go on to use those drugs. So, it’s not a gateway drug. It’s illogical to make that sort of statement. It would be like saying that “the last three presidents of United States used marijuana before they became president. Therefore, marijuana is a gateway drug to the white-house.”

Skeptic: Those who use crack cocaine didn’t use alcohol or tobacco before using marijuana?
Hart: Most used alcohol and tobacco before they used crack cocaine; of course, they also drank water or ate a fruit. Crack cocaine users engaged more in petty crimes than those who use marijuana, so we can also say petty crimes is a gateway to harder drugs. You can think of any number of behaviors associated with people who go on to use heroin and call those behaviors gateway, but that’s not a proper scientific conclusion to draw.

Skeptic: Is there a difference between crack and cocaine?
Hart: Pharmacologically, there is no difference. The major thing the people are seeking when they use cocaine is the cocaine base. Powder cocaine contains not only the base, but a hydrochloride salt that makes it stable and decreases the likelihood to smoke it. If you want to smoke it, you have to remove the hydrochloride portion, which does not contribute to biological effects of cocaine. When people are describing the difference between crack cocaine and powder cocaine, what they are really describing is the difference between the ways the drugs are taken. The onset of effects is faster when you smoke it than when you snort it. But you can dissolve powder cocaine in water and inject it in your veins and have the same effect as you do from smoking the crack.

Skeptic: Since it hits the brain faster, is crack more addictive than cocaine?
Hart: Smoking crack cocaine and injecting powder cocaine dissolved in water hits the brain at the same speed. Nonetheless, this is one of the arguments that some have made. But there is no drug that we punish as a result of the route of administration besides crack cocaine and powder cocaine. And we make that distinction in the United States because crack cocaine was associated with poor black people. When we look to powder cocaine in United States in the early 1980s, there was no drug that produced more violence than powder cocaine, but no one passed new laws, in part, because the people engaged were not black people; they were primarily white people. So as a society we are not being honest about this.

Skeptic: People think one dose is enough to get them addicted. Can you explain why this is not true?
Hart: By definition, drug addiction is behavior that disrupts your psychosocial functions, your job, your family life, and the behavioral disruptions have to occur on multiple occasions. So, if you use a drug once and you have a disruption once, by definition that is not an addiction. Addiction requires work. There is no one hit of anything that causes anyone to get addicted. People make these statements based on pure hyperbole attempting to get an emotional rise out of the listener.

Skeptic: How addictive is tobacco compared to other drugs?
Hart: At 1 in 3, or 33% of people who smoke will become addicted to tobacco, that is the drug that we say causes the most addiction. By comparison, 15% of those who use alcohol will become addicted. The rate for marijuana is about 10%. Heroin is about 25%, and cocaine (and crack cocaine) ranges from 15% to 20%.

Skeptic: Psychopharmacologist David Nutt, author of Drugs Without the Hot Air, published a study in 2010 that called alcohol the most harmful drug. Do you agree with this? 
Hart: I am a fan of David’s work and of his advocacy to educate the public, and I admire what he does. I think he tries to make the public understand that when we think about whether a drug is toxic, we have to look to multiple measures. And in one measure alcohol may be seen as the most toxic drug. For example, when we think about withdrawal from a drug, when people abruptly discontinue long-term use of a drug alcohol is clearly the most dangerous because you can actually die from alcohol withdrawal. You can’t die from withdrawal from heroine, crack cocaine, tobacco, or marijuana. When trying to determine the potential toxicity of a drug, it all depends on what measure you’re looking at.

Skeptic: I’ve heard a lot of comments about how addictive people behave. For example, some people say crack users are “zombies”. I’m not sure what it means to be a drug zombie, but what is it people are thinking when they use such expressions to describe people under the influence of a drug? That is, how do addicted people behave?
Hart: I’m a psychologist who studies human behavior. But all of us behave, and we most of us think we’re experts in understanding human behavior because of this fact. But most people are not experts and that’s part of the problem with such subjective and anecdotal reports. People see somebody misbehaving in some way and they know that person uses a drug. Therefore, they conclude that the misbehavior is caused by that substance. No! You can’t draw that conclusion. There are multiple factors at work, and these multiple factors need to be teased apart. You have to consider the person’s psychological history, whether or not other drugs were on board, whether the person was sleep deprived, whether the person interacted with someone who angered them, etc. People often fail to consider these other factors. That’s why anecdotes alone are insufficient to provide an adequate explanation of behavior.

Skeptic: In one of your experiments you gave participants two choices, money or drugs. What did you find and what does it mean?
Hart: Of the things people say about drugs users, particular about the drug addicted, is that they only respond to their drug of choice: if you give them an opportunity to use their drug, they’re going to take it over anything else. It was a simple experiment in which we had escalating amounts of money that we offered subjects. We found that when you increase the monetary value, you decrease their choice to take the drug—they choose money instead; they behaved rationally.

Skeptic: Why do people get addicted?
Hart: It’s a difficult question and one that science should be really focused on. Recently we’ve been concentrating on finding biological mechanisms of addiction. But frankly we’ve not found any that are compelling so we must look to other things as well, such as co-occurring psychiatric illnesses like depression, anxiety, and schizophrenia, which increase the likelihood of being addicted. Addiction is a condition primarily characterized by not tempering your behavior when it comes to certain drugs. But there are people who do not temper their behavior in a wide variety of domains, not just with drugs, because they just haven’t learned the skills to do that. So, that increases the likelihood of becoming addicted if they indulge in drug-taking behavior because taking a drug requires a person to be responsible, for example when driving an automobile. You can’t be irresponsible driving automobile; you might hurt yourself or someone else. If you haven’t learned those responsibility skills, it increases the likelihood of you becoming addicted. If you don’t have many alternatives in life that are better than drugs, it increases the likelihood of you becoming addicted. All these factors are critically important when we’re trying to determine why someone became addicted compared to someone else who did not.

Skeptic: You mentioned biological mechanisms for addiction. There is the dopamine hypothesis, but you mentioned in your book that there are problems with it. Can you clarify?
Hart: Let’s talk about the simplistic version of the dopamine hypothesis first. Drugs like cocaine and amphetamines increase dopamine, which in turn increases pleasure. So researchers said drug users are trying to increase their dopamine and so dopamine was considered to be a critical factor. This was an important theory because it helped us to organize several types of experiments, but it came about in 1960s when we had identified only five or six neurotransmitters. Today, we know about more than 100 neurotransmitter substances and yet the theory hasn’t been appreciably updated. So, we’ve learned a lot about the complexity of the brain in terms of how neurotransmitters interact with each other. Rather than one neurotransmitter being released at one time, there are multiple neurotransmitters that are released together in order to produce effects. And, sometimes, they are co-localized in the same cells. The old dopamine theory does not take into account this new knowledge. For me, the dopamine hypothesis is too simple to explain complicated behavior. Plus, we have some observable information that can help people right now: Does the person have a co-occurring disorder? Is the person responsible? We can manipulate many variables to help people now; you can’t assist drug users immediately with the dopamine hypothesis, and it doesn’t help anybody in treatment; it doesn’t help in any practical level. It’s on the level that science is trying to figure it out and we’re not close, if we’re talking about dopamine.

Skeptic: What about pharmacological treatments for drug addiction, such as cocaine?
Hart: A large part of my career has been spent trying to develop medications to help people with cocaine addiction, but we have been unsuccessful in finding a medication that works. It seems the best medication for cocaine addiction is cocaine itself. In Switzerland heroin is used to treat heroin addiction, and successfully so. When we think about treatment there are a variety of components that are necessary, not only the drug: psychosocial support, therapy to figure it out what’s going on with the person’s addiction, do they have employment, do they have a social network? All of these factors are incorporated into the heroin treatment program in Switzerland, and it’s been successful. You can do a similar thing with cocaine, but you have to have all these other auxiliary components in place.

Skeptic: What are the harms caused by amphetamines?  
Hart: The first lesson people should really know is that there are potential harms for all the drugs that we’ve talked about it. However, when you only emphasize the potential harms, people who use drugs stop listening to you, because they know there are other effects (that’s why they use them). The major concern about amphetamines is that they have a powerful effect on the cardiovascular system; it increases blood pressure and heart rate. This is not good for people who have a compromised cardiovascular system; they should not take large doses of amphetamines. Amphetamines disrupt sleep, and sleep deprivation can cause several physical and psychological problems, even without any drugs use. Amphetamines also disrupt food intake, which is critically important for the proper functioning of the body. Those are the concerns that people who take amphetamines should be aware of, rather than other concerns that are often emphasized in the media and even by scientists. About cognitive decline, amphetamines are approved to enhance cognitive functioning in order to treat attention deficit disorder. So, the notion that amphetamines are causing cognitive dysfunction is simply inconsistent with the history of behavioral science we have with these drugs.
Skeptic: Another idea you hear a lot is that marijuana or cocaine kills nerve cells. Is that any evidence of that?
 Hart: Any psychoactive drugs in large doses can kill brain cells. However, these doses are so large that they the drugs would be so unpleasant to humans that they wouldn’t take those doses again after experiencing their effects, if they survived it. These doses are 20-80 times of what people usually takes. In addition, there is no evidence that long-term use of doses within the range that humans take produces neurotoxicity. Neurotoxicity certainly can happen, but the likelihood that it happens to people using drugs within the range that humans take is very low.
Skeptic: Why do you advocate for decriminalization rather than legalization of drugs?
Hart: Of all these drugs that we’ve talked about, nicotine in tobacco is probably the one that kills you with the smallest amount of it. 50 mg of nicotine would kill half of us. In contrast, with 50 mg of cocaine or heroin, you just feel really nice. So, we have to think why nicotine is legal even though so little of it is necessary to kill people. It’s legal because we have societal structures, we have education about nicotine, and we know how to keep people safe with it. One cigarette contains 1 mg of nicotine and one pack contains 20 cigarettes. It requires people to smoke multiple packs immediately to kill themselves. We’ve packaged nicotine in a way that substantially decreases the likelihood of someone getting immediately harmed. We have to figure out how to package other drugs and educate people in a way to keep them safe. We have not done that yet, because we don’t have the social structures in place. I see decriminalization, in part, as the intermediary step to regulation, like we regulate alcohol and tobacco. But we have to put those structures in place to keep people safe, because all of these drugs are potentially dangerous, although all of them can be used safely.
Skeptic: We can compare different places (countries, states, cities) with different drugs laws (prohibited, decriminalized, legalized) regarding several outcomes, such as rates of drug use, drug-related deaths, drug-related homicides, and crime. What can we say about these kinds of measurements? That is, what are the effects of decriminalization and legalization on such outcomes?
Hart: I think a comparison of Portugal and the U.S. would be instructive here. In 2001, Portugal decriminalized all drugs including heroin and cocaine. Overall, they have increased spending on prevention and treatment, and decreased spending for criminal prosecution and imprisonment. The number of drug-induced deaths has dropped, as have overall rates of drug use, especially among young people (15-24 years old). In general, drug use rates in Portugal are similar, or slightly better, than other European Union countries, and they are doing better than us in the U.S. In other words, Portugal’s decriminalization has been successful. No, it didn’t stop all illegal drug use. That would have been an unrealistic expectation. Portuguese continue to get high, just like their contemporaries and all human societies before them. But they don’t seem to have the problem of stigmatizing, marginalizing, and incarcerating substantial proportions of their citizens for minor drug violations. Together, these are some of the reasons that I think decriminalization, or even legalization should be considered as potential options in the United States.
Skeptic: If you were the director of drug control polices in United States, what would be your short- and long-term policies? 
Hart: I would first work to decriminalize all drugs so that people no longer run the risk of being incarcerated for drug possessions. Too many of our citizens are languishing in prison unnecessarily for drug violations. I would also work to change the way we educate about drugs such that it would no longer be acceptable to exaggerate the harms of drugs as a scare tactic. Education would first function to keep our citizens safe. In the long-term, I’d work to regulate all drugs so that we decrease the likelihood of drug users obtaining and using drugs that are adulterated with chemicals more dangerous than the drugs themselves. My major goal as director would be keeping people safe, with the understanding that some people will use drugs as humans have always done.
Skeptic: What was your goal when you wrote the book High Price?
Hart: The goal was to communicate to the general public. The first goal of the scientific community is to keep their lab funded and, sometimes, this is inconsistent with larger goals of society. The research on drug abuse is mainly focused on the bad effects of drugs, because the major funder is National Institute of Drug Abuse, which funds 90% of world’s research in this area. National Institute of Drug Abuse goal is focused on the bad things that happen with drugs, and scientists are shaped by this goal. Society at large has the goal of being safe, and scientists have the goal of “don’t use these drugs”, so it’s inconsistent. I wanted to make the public understand that their goal and the scientist’s goal are different, that their goal and the goal of the police man who is talking to them are different, and that their goal is also different from the goal of media person who writes stories about drugs.
Skeptic: At Skeptic we advocate for evidence-based instead of faith-based thinking, as do you. What do you think is the best approach to shift people from faith-based to evidence-based thinking?
Hart: When you try to change people’s view about something that they think they know, in some cases they feel threatened and insulted because they worked really hard to acquire this knowledge. Now you tell them they’re wrong, and that’s hard for most of us to accept. So, the approach has to be one that acknowledges the work they have put in to acquire their knowledge, even if their knowledge is outdated or inaccurate. On the one hand, you say “you know, I was just like you, I got fooled. They fooled me, like they just fooled you. Here it’s how I see it differently now, and how you can see it differently too.” You have to make some connection with the audience, with the people, in order to move them along. Sometimes we all get impatient because we don’t have the time to make the connection, so we say “the evidence shows this and you’re wrong.” That usually doesn’t work. I understand why people become impatient because they hope others will just follow the evidence like they do, but it doesn’t work that way on a regular enough basis.
Skeptic: What do you think is critical to being a good scientist?
Hart: Always to try to disprove your own hypothesis. If you’re not doing that, you increase the likelihood of following dogma. So the critical thing is to design experiments that can disprove your own hypothesis.

Skeptic: Thank you for this thoughtful interview.