You can't teach an old dogma new tricks

The institutionalised falsities that still plague scientific study today.
13 September 2022
Presented by Chris Smith
Production by James Tytko.


Wrong way sign


This week’s show conveys how surprisingly susceptible science is to dogma. We uncover the alarming oversights which have mitigated progress in disciplines like zoology and medicine for decades. Corrupted for years by false assumptions, the failings in these fields can be extremely difficult to overturn. We hear from scientists going against the grain to dispel mainstream myths from their respective areas of study, and also provide a protocol for dodging dogmas moving forward...

In this episode


01:04 - Is Zoology sexist?

Has our understanding of relationships in other animals been misinformed by outdated views on gender roles?

Is Zoology sexist?
Lucy Cooke

James Tytko spoke with zoologist and TV presenter Lucy Cooke about a dogma which has plagued the field of evolutionary biology dating back to the man who started it all off, Charles Darwin himself. They met at his old stomping ground, Christ’s College, in Cambridge…

James - So Lucy, thanks so much for joining us. The topic of this week's show is dogma and dogma, for people who don't know, is a belief authoritatively laid down without being questioned or scrutinized. And I wondered Lucy, if it was alright, if we started this discussion about dogma and your recent work with a bit of an activity, I've got some myths, some popular falsities, if you like, about animals that I wonder if you might have a go at debunking for us. And the first one is that you'll often hear people describe someone as being as blind as a bat. Now are bats really blind?

Lucy - No, they're not blind. No, in fact fruit bats can see better than we can. You know, you'd probably quite like to have the eyes of a fruit bat. Very handy if you were looking to lead a sort of crepuscular existence. In the 16th century, it was an Italian Catholic priest who worked out that they were actually using echolocation and he did some sort of barbaric experiments where he actually removed the eyes of bats <laugh> before letting them loose, and found that they could still navigate.

James - Ostriches burying their heads in the sand. Is that something they actually do?

Lucy - No, they don't bury their heads in the sand. And what that might come from is two things - One, they nest on the ground. So they actually have these communal nests, ostriches, that one female will look after, or it might even be a male or one ostrich will look after. And so obviously when they're putting their head down to rearrange the eggs and turn them around, that might look from a distance like they're sticking their head in the sand.

James - Thank you, Lucy. Throughout the course of that exercise, what I've been trying to get at is that sometimes we spread falsities and can be susceptible to believing untruths because it's convenient to us, because they make for a good story. But believing something because it's convenient is diametrically opposed to what we think of as science. But you've been showing that in the case of evolutionary biology, scientists have been guilty of perpetuating a theory because it's convenient, because it's what they know.

Lucy - Yes. Yeah. It was shocking for me to discover this really, but evolutionary biology turns out to be sexist. Darwin himself, here we are in the college where Darwin learnt zoology himself at Cambridge. And he's a hero of mine, you know he's the reason I studied evolutionary biology because there would be no evolutionary biology without Charles Darwin. He was an incredibly meticulous scientist, but he was also a man of his time. And that time was the Victorian era, a time when women couldn't vote and their place was in the home. And so when he came to brand the female of the species, she came out in the shape of a Victorian housewife. Passive, coy and submissive by default. And then because Darwin said it, all the scientists that followed in his wake for over a hundred years suffered from a chronic case of confirmation bias. I was amazed that science could be so vulnerable to cultural bias. You sort of think of it as being impervious and the scientific process rinsing out that kind of cultural bias, but actually no.

James - This revelation you had led you to write the book that I'm holding in my hands now, which is quite provocatively titled 'Bitch'. But I think I'm allowed to say that? So I'm going to take that opportunity. Can you give us a flavor of where this typical narrative of the plucky male overcoming the other suitors and the prize being the submissive female, where this damsel in distress isn't reflected by the actuality?

Lucy - Well, I mean, there are dozens of examples that I could choose. Probably the one that led to the idea that Darwin was perhaps wrong, <laugh> being bust open, was langurs. Langers, which are monkeys, you find in India, beautiful live creatures with these lovely sooty faces. And it was actually Sarah Blaffer Hrdy, who's an American anthropologist. And she noticed that the females were anything but coy and chased. And they were actively soliciting sex with males outside of their group. She was, really the first scientist rather than to sort of go, 'oh, hang on that doesn't fit the paradigm I'm going to ignore that', which is what everybody previously had done whenever they came across sort of the promiscuity of the lioness for example, they just sort of walked away and said, 'oh, we're not gonna look at that because that doesn't fit.' And she found that it was connected with infanticide. Male langurs are infanticidal. If a new male takes over a territory, then he wants to meet with the females in that territory as soon as possible. But if they're nursing young, then they're not available. But if he kills the babies, then they're going to come into oestrus and then he can mate with them. Now as a counter strategy against infanticide, the females will have sex with every male in the neighborhood. And then the males are less likely to kill the babies of a female that they've recently mated with. These are not the coy chased females of Darwin's dreams.

James - I want to go back to something you said a bit earlier and to lift the veil on how science is susceptible to human fallibility, our confirmation bias. And I wanted to ask how much this dogma that you've been trying to unearth still hangs over evolutionary biology today. Once a dogma has taken hold, how easy is it to reverse the narrative?

Lucy - It's surprisingly hard. I mean, Sarah Blaffer Hrdy, who I talked about in the first instance, she first started challenging these stereotypes that were established by Darwin back in the end of the 1970s. That's 50 years ago now, right? So you'd think we would've got over it by now and the sexist stain would've been washed out of evolutionary signs, but that is not the case. So one of the sort of fundamental principles that underpins this idea that males are more variable and the dynamic drivers of evolution and females aren't is Bateman's paradigm. I won't go into it all, but it's based on an experiment on fruit flies that took place in the 1940s and that underpins these stereotypes, okay? There's another scientist, Patricia Gowaty, who has done a number of experiments in order to question that. And she's replicated the experiment, she's gone back to the original notes, et cetera, and she's found that the idea that this underpins a universal law, that males are promiscuous and females will be chased and choosy is bunkum right? It's just not true. And yet her papers are considered to be ideologically driven. So they're often not taught.Bateman's paradigm is still found in pretty much every textbook you'll find and Patty's papers will probably not be referenced alongside them. So, you know, we've still got work to do.

A serotonin molecule

09:19 - Serotonin: the depression theory dogma

The theory of chemical imbalance was long thought to be the cause of depression, but this is now refuted

Serotonin: the depression theory dogma
Joanna Moncrieff, University College London

That science is vulnerable to dogma is even more troubling when we consider the very important role it has to play in keeping us physically and mentally healthy. Science underpins the practise of modern medicine. Last month, a paper published by a team at UCL demonstrated that the working theory for the cause of depression, and what has informed the characteristics we look for in antidepressant drugs, did not stand up to scientific scrutiny. Speaking with James Tytko, Joanna Moncrieff…

Joanna - One theory about the causes of depression that has been very widely promoted has been the idea that depression is caused by abnormally low serotonin concentrations or activity levels in the brain, which could be corrected by these drugs that were thought to increase levels of serotonin. And it is a theory that was told to very many patients about what antidepressants were doing and what the nature of their symptoms consisted of.

James - What are the problems with this theory that you've found?

Joanna - The problems are that the evidence showing any abnormalities of serotonin in people with depression is weak, inconsistent, and really just basically doesn't stack up. All the different main areas that have tried to in some way gauge what's happening in the serotonin system, in people with depression, and compare it to what's happening in people without depression. There was no convincing evidence from any of those areas of research that there was any between serotonin and depression and certainly no evidence that people with depression had abnormally low serotonin levels.

James - So if we take this chemical imbalance theory of depression as something that's unhelpful, why do you think it's persisted for so many years? Why has it taken until you and your team of researchers to start to question this theory?

Joanna - The theory was established in the minds of people by very well funded, very widespread promotional campaigns run by the pharmaceutical industry, starting in the 1990s and lasting for most of a couple of decades. So that's how it became really well established. Why it persisted is a good question because many leading psychiatrists and researchers have known for some time that actually the evidence for links between serotonin and depression was not convincing or consistent. And yet no one has informed the general public until now, until the media coverage of our recently published paper. And I think that is because many psychiatrists, even though they know that the evidence for serotonin is not strong, really want to believe that the drugs that they prescribe work in a clever and sophisticated way by targeting some underlying biological abnormality. And they don't want to think about their drugs as drugs that change our normal mental states, because that is a bit worrying and would probably make people less likely to take them.

James - There are of course, a lot of interested parties in this scenario, not least the people suffering from depression, but you've mentioned the drug companies as well. What's it been like to be a scientist going up against the mainstream like this? Have you come under pressure? What has the experience been like personally, if I may?

Joanna - Some of my colleagues and many other psychiatrists that most of whom I know by reputation, if I don't know them personally, have clearly been outragedb that I have raised questions about the action of antidepressants and also really that I have suggested that depression might not be due to a specific biological abnormality and that it might be time to think about depression in a different way.

James - Despite the fact that as you mentioned, a lot of them probably have known and would agree with you.

Joanna - Even though the majority of people have said, 'of course we knew that the research on serotonin didn't stack up, of course we knew the low serotonin theory was much too simple. It's much more complex than that.' Despite that, most people want ordinary people to carry on believing that, even though there's no evidence to support the theory that depression is due to low serotonin, it must be due to some sort of other biological abnormality and antidepressants must work in that way. And I think they really deeply don't want people to realize that there are other ways of thinking about depression and other ways of thinking about what antidepressants might be doing.

James - I suppose, is this a story of victory for science over dogma? Or do you feel a bit pessimistic about the role of science in reaching this conclusion or the journey to getting here? How have you felt as a scientist about that process?

Joanna - I mean, I've been making the same points about antidepressants essentially for many years now. Clearly the surprise that greeted the publication of our paper shows that I hadn't got through to many people because most people were still completely convinced that depression had been convincingly demonstrated to be due to a chemical imbalance. So I'm really pleased that the message has got out to more people. And I hope that it will encourage people to question and to be more skeptical. The backlash that I've got from colleagues and from other people in the profession and also in the media makes me very worried about the current state of science. It makes me worried that there are some people who really feel that it is okay to shut down debate. It is okay to characterize a perfectly logical, plausible and well supported opinion as being beyond the pale and something that someone shouldn't be allowed to say. And I think that's a worrying situation. I really hope that the message does get out to more people, because I think it's incredibly important that people are able to make properly informed decisions about the things that they do to their body. And if people don't have information about the sort of drugs that antidepressants are, the fact that they are drugs that change our normal brain chemistry, the fact that drugs that change brain chemistry may have detrimental long term effects. If people don't have all that information, they are not able to make properly informed decisions about whether or not to take antidepressants.

An operating theatre team performing surgery

16:21 - Undoing dogmas in medicine

The answer is 17 years, what is the question?

Undoing dogmas in medicine
Ian Roberts, London School of Tropical Medicine

So far, we’ve shown that some of the false assumptions on which many science-led sectors are based can be very deeply rooted, making them extremely difficult to expel. If we continue to look at medicine as an example, it is often quoted that it takes 17 years for research evidence to reach clinical practice, such is the hold these institutionalised dogmas have on the discipline. One man very familiar with this is Ian Roberts, from the London School of Hygiene & Tropical Medicine, who’s been looking at the potential benefits of a drug that can cut the risk of bleeding during surgery.

Chris - Ian, welcome to the programme. What put you on the trail of this in the first place?

Ian - Tranexamic acid is a drug that was invented the year I was born, which is about 60 years ago. It was widely used to reduce bleeding after tooth extraction and heavy menstrual periods. And then surgeons started using it because it reduces surgical bleeding and the need for blood transfusion. And it really, really does work. There have now been over a hundred thousand patients in randomised trials; without any shadow of doubt tranexamic acid reduces bleeding in surgery by about 25% and reduces the need for blood transfusion by about a third to a quarter.

Chris - So what's not to like, Ian.

Ian - I don't know. There's a remarkable reluctance of doctors, surgeons, anaesthetists to use it. In fact, we've just started a collaborative campaign with the Royal College of Surgeons, the Royal College of Anaesthetists, the Royal College of Physicians, all these eminent Royal colleges to try to encourage doctors to consider the use of tranexamic acid in all patients having inpatient surgery. And also patients should ask for it too.

Chris - Stepping back a section, usually physicians are loathe to do something because there is a perceived risk that something bad will happen if they depart from established dogma. That's what this programme ultimately is all about, isn't it? So what are people worried about then if they were to use this? What sounds like the blood clotting equivalent of aspirin - it is wonderful for health in all ways - what are they concerned about.

Ian - Drugs that reduce bleeding sometimes increase the risk of unwanted clotting causing heart attacks and strokes and things. And so they've got this kind of mechanistic sort of expectation, but it's just not born out by the large scale randomised trials. It's a sort of belief that's not completely unreasonable, but trying to shift that belief with evidence, which is I think what it's time we did, is the hard thing.

Chris - It sounds to me a bit chicken and egg here, where there's this perception of risk and so people find it difficult to then do the studies that would prove that there isn't any risk and because they don't have the evidence, they don't act on it. And it goes round like a self-fulfilling prophecy.

Ian - Well, except that we have the evidence with people have been doing randomised trials of tranexamic acid in surgery for about, I don't know, 50 years. And now we've got lots of evidence. There was another big trial published in the New England Medical Journal a couple of months ago. And it was just the same, highly significant reduction in the risk of bleeding, major bleeding, potentially life threatening bleeding, and no increase in the risk of thromboembolic events. We have a job being rational in a way.

Chris - Do you think this sort of thinking infests medicine comprehensively, or is it just something about surgery?

Ian - Medicine is like this huge super tanker that changes course very, very slowly because it's all about habits. Doctors might say they are up to date with the evidence and they think of every individual patient that's in front of them, but actually a lot of it is habits and, "patients like this, I normally manage like this." And so changing habits is quite difficult. With the surgical issue, the opportunity to change habits is that there's a bit of a crisis at the moment. So there's a blood shortage in the NHS. I think it's partly due to COVID and summer holidays and all of that. But blood stocks currently are really low; they're halfway where they should be. And if they get any lower, they'll have to possibly postpone elective surgery and that's a real disaster for patients. So I hope that surgeons and anaesthetists are going to respond to this crisis and start using tranexamic acid in surgery to reduce unnecessary blood use.

Chris - It certainly sounds like you're making a strong point. One has to wonder though, to what extent we are actually shooting ourselves in the foot with this sort of mentality. Because on the one hand we are very risk averse because we don't want to do harm because if we do harm because we depart from established guidelines, then the authorities come down on us like a ton of bricks. On the other hand, we could potentially be costing lives through inaction because of this sort of anonymity. So how do we break the cycle? And what would you say to Joanna who we just heard from about the fact that she's lobbying saying serotonin and depression are not linked in the way that we've been taught dogmatically for years, we need to rethink.

Ian - It's almost like sins of omission and sins of commission. So patients can die because we don't do something and that's not weighted as seriously as if patients died because we did something. I don't know if that's the way humans are hardwired. All I can think of to do is to keep on trying to present the evidence in different ways, emotionally appealing ways. I've learned over the years that humans aren't really rational. We're sort of a fizzing ball of emotion. So you've got to tap into people's emotions if you want to get practice change.

Chris - I mean, taking a contemporary example just to finish the Covid vaccines, for example, which broke the mould in terms of how they got invented, how quickly they got through trials and things, and the technology they were founded upon. People have been working on those mRNA technologies for decades in some cases. And no one had got close to making a vaccine, which now Pfizer and Moderna are fighting over who owns what, because they're regarded as the biggest breakthrough in infectious diseases in cancer in the last two decades.

Ian - I think that's a sort of example of the point that I'm trying to make: the NHS seems like a very slowly moving super tanker, but during the COVID crisis, it just suddenly got very nimble and started changing direction very quickly. I got redeployed back to the intensive care unit at the Royal London hospital, and I was just amazed how quickly they could change things when there's a crisis. People can respond really rapidly. So to some extent, I think in order to change the thing you're trying to do, trying to implement, has to be the solution to some crisis.

Chris - Yeah. I'd rather not have a COVID crisis every day of the week though, but I would like to see a faster pace of change. Ian, thanks very much for joining us to talk about the dogma in medical practice and changing medical practice. That's Ian Roberts, he's at the London School of Hygiene and Tropical Medicine.

A cartoon genderless CGI figure with a blank speech bubble above their head

23:53 - Measures to mitigate myths

How science communicators and public can avoid perpetuating dogmas

Measures to mitigate myths
Claudia Schneider, University of Cambridge

We’ve heard about the damage dogmas can do to how science is conducted. So how can we deal with them? Well, the best way is to be able to nip them in the bud early. Claudia Schneider works at the University of Cambridge’s Winton Centre; she’s interested in how best to communicate science to the public. This, it’s argued, can help people to recognise dogma and misinformation before it becomes embedded in our thinking and retards progress…

Chris - Claudia, what's your perception of how people judge science, or what's their perception of science and how it's practised at the moment?

Claudia - So I think science has definitely come into the spotlight in the recent years during the pandemic, we've seen a lot of signs in the press briefings, graphs and data being shown. And that's good because it shows that scientific insights are being used to help make decisions. But I think having science in that spotlight and the media might have also contributed to a public feeling or almost expectation that science can provide us with answers, that it can sort of tell us what to do. We've heard this mantra of "follow the science" and it's really tricky because science comes with a lot of uncertainties: in the data we use and modelling the statistics and the insights that we have and what we know constantly changes. So I think it's very important also for the public to know what science can do and what it cannot do and what it can't tell us.

Chris - I mean, personally, as someone who is involved in science radio programmes and therefore the communication of science, one of the things I think is a big challenge is that life and the way that we tend to operate as human societies, it's very guideline and law driven. We tend to make people think or plan in black and white and science is completely not like that in the sense that science is all about hypotheses and narrowing the gap in our understanding. But nothing's certain, nothing's a fact, although I know notwithstanding what Ian said about tranexamic acid just now, but my view is that people find it hard to understand what scientists are talking about when they talk about uncertainty. That's the difficulty

Claudia - Absolutely. Communicating in a way that is clear and helps to inform the public, not trying to persuade them to believe a certain thing, that is really the key here. And that's actually one of the good evidence communication principles that we've put together at the Winton Centre to try to inform, not persuade. That goes together with, when we communicate: offering balance. So talking about the harms and the benefits to help people understand disclosing uncertainties. Saying, "what is it that we don't know" that also acknowledges that what we know will change over time stating the evidence quality. So telling people, "what is that information that I'm giving you? What is it based on? What is that evidence? Is it reliable? Is it trustworthy and helping to preempt misunderstanding?" So I think if we adopt these communication strategies, be it in the media, in our personal life or in government that might be able to help people to understand the scientific process better and to spot potential misinformation.

Chris - I first came across those five guiding principles that you just summarised there during the COVID pandemic. And I was very impressed by them because they nailed it. But I was left thinking, well, why did no one say this to us before?

Claudia - I think, and these have also been voices raised in the literature and in the field, that there's this fear that if we tell people all the things that we don't know and all the uncertainties, maybe that will undermine public trust, they're like, "well, what do these scientists even know?" And that's a relevant question and a valid one. And we've actually, in some of our studies, empirically researched this by running studies where we looked at does it happen or not? And in studies where we compared the more balanced evidence communication with more one-sided persuasive approaches, we've seen that it does not seem to undermine trust. And people actually appreciated being presented openly and honestly with the kind of evidence and. They were more willing to listen to them.

Chris - So there was a dogma among scientists and science communicators that the public wouldn't welcome risk and a perception or communication of risk. And you've broken that dogma down by saying actually they do.

Claudia - Generally, as humans from psychology research, we know that we do like certainty and uncertainty and ambiguity is hard to deal with, but it is important to not let that stop us from communicating it because telling a simple story and a neat narrative that over-claims and presents things with unwarranted certainty - that can come back to haunt us. If things change, it can erode credibility in a communicator, it can erode trust. And on the other hand, if we really treat people as able decision makers, able to handle uncertainty, then we allow them to also get more comfortable with the uncertainty down the line and be able to spot when someone approaches us telling us, "this is what you should do." And then they might ask, hang on a minute, what's the evidence base. And that's good because that way they can participate in the scientific discourse.

Chris - What would be your advice then to people who want to defend themselves? I use the phrase mentally immunise themselves against dogma or falling for dogmatic communication. How should people make sure that they're, they're better prepared not to just absorb a fact and regurgitate it. What sorts of questions should people be asking when they're confronted by something that someone says is a fact?

Claudia - Yeah. It might be helpful to come back to the five principles, which are relevant both on the side of the communicators - so we think, if I communicate something, have I made sure that I disclose what the kind of evidence is that I also talk about what I don't know - but then also at the receiving end that when we read something on social media, when someone tells us something that we really ask these kind of questions, right? Like is this more persuasive or do they offer a balance? Do they talk about the pros and the cons? Are they trying to inform me, are they talking about the possible uncertainties or where the evidence came from, and that then allows people to ask questions and to judge the quality of that particular information, that particular communication that someone is trying hard for them to believe.

Chris - It looks like, as one former Conservative cabinet minister who was a science minister said to me, this is the time when the public have got more trust in science than probably they've ever had. And probably COVID has done that. It strikes me that scientists and science journalism is in a very strong place at the moment. People are looking to science for the direction of travel. How do we make sure we don't go in the wrong direction from here?

Claudia - I think the key here is for communicators to demonstrate trustworthiness, to make sure that we communicate in a way that we are worthy of people's trust, which goes back to this idea that we should be honest and open, say what we know, but also say what we don't know, because sometimes it is just not a simple story. And then don't stop there, but also say, "well, this is what we're doing to find out" and making clear that our insights, our advice can change and that is actually okay, because that is what should happen in the scientific process. And that we don't need to hold on to dogmas that we have believed for a long time.

Chris - Claudia, thank you very much, indeed, for putting it so clearly. Claudia Schneider, who's from the Winton Centre at the University of Cambridge.


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