As a physician for more than three decades and a Molecular Biologist before that, I know a lot of science and medicine (I also keep up with the literature.)

I find that people hold on tightly to their beliefs about health matters, and many don't know how to search or evaluate the literature to inform their beliefs. I don't mind this; I don't know anything about an enormous number of things, but I like to learn. An extreme example of this is anti-vaxxers, but there are much 'softer' positions that are equally incorrect.

When people find out socially that I'm a doctor, they want to discuss Big Pharma, conspiracy theories (e.g. doctors know the cure for cancer but are withholding it to make money), want to know if I'm a "Lyme-literate" doctor (Southcentral PA is a Lyme hotspot, so it's a very real concern here), or want to discuss a particular disease and what causes it. I don't take offense at these approaches, because I hope to help people understand, and sometimes I actually succeed.

But sometimes they go nowhere, or worse. For example, if I cite a study on dogs, they'll reply, "But dogs aren't people!" without knowing that dogs are an incredibly good model for human disease.

Yesterday I was speaking with a breeder about a disease my dog has. She doesn't trust vets (they're in it for the money) and said it wasn't possible that my dog had (x), that I shouldn't have (a radiological study to determine the extent of x), that I should just change the dog's diet. When I said I've treated the same disease in people and this test is necessary, she shouted, "BUT DOGS AREN'T PEOPLE!!!"

I told her that she was right, that dogs aren't people, but they are an incredibly important model for human disease, and that many breakthroughs in medicine were thanks to the study of the same disease occurring in dogs.

She then snorted that doctors are in it for the money.

I like being social, I like discussions, and sometimes the discussions are fruitful and satisfying. Sometimes they're only frustrating. I don't like being rude, so I engage in these discussions not knowing which direction they'll take.

I have never said, "I don't discuss medicine off-duty". Or "I don't discuss science." I would feel I was being rude and antisocial. If I just change the topic, it's clear I simply disagree.

How can I break this cycle?

Edited to add (in response to comments): I rarely tell people I'm just meeting that I'm a doctor. If I'm asked directly, I'll answer honestly. I love science and will bring it up (did you hear about [amazing breakthrough of the year]?) but I will not bring up medicine unless it's with friends who know I'm a doctor and it's something funny. I address people at their level; you can't communicate effectively with a patient (or anyone else) without taking note of their own level of comprehension and using it yourself. (It's not an "I'm smarter than you" thing. I may be smarter about some things, but I guarantee I'm downright stupid when it comes to technology and a bazillion other things.) My work has been caring for people, and I care deeply about people who put their health in my hands. Can't say that extends to everyone I meet, though. I write much more formally than I speak. Finally, the dog conversation happens a lot because I used to be a breeder (Border Collies, the best dogs in the world!) and I know a lot of dog people.

[Btw, I love dogs and don't like the thought of experiments on dogs or any other animal. I'm a "flexitarian", which means I rarely eat meat. That's because I love animals, not because I think meat is unhealthy. But scientists work on dogs despite my feelings.]

Dogs have approximately the same number of genes as humans, most of them being close orthologues... Importantly, pet dogs share also the environmental conditions of their owners and are thus not only affected by genetic traits but also by “life style.” Hundreds of spontaneously occurring common canine conditions are analogous to human diseases such as diabetes, cancers, epilepsies, eye diseases and autoimmune diseases, not to mention the high numbers of rare monogenic diseases.


16 Answers 16


There's usually not much benefit in arguing in a situation such as you described. When people have passionate opinions on topics, it is extremely difficult to discuss a different perspective without one or both sides becoming defensive (or offensive).

This Scientific American article discusses two of the major obstacles in perspective-changing: confirmation bias and the backfire effect.

Once an emotional response to a topic occurs (such as shouting, or outright refusing to acknowledge a point), it is best to disengage, at least temporarily. A change of topic gives the person you're talking with an opportunity to let their emotions cool, at which point they may be more willing to listen (or not).

A simple statement of concern about the disagreement is usually enough to get them to agree to a topic change:

I don't want to start an argument, and it seems like we disagree pretty strongly on this topic. Can we talk about something else?

The Scientific American article also offers some good general strategies:

  1. keep emotions out of the exchange
  2. discuss, don't attack (no ad hominem and no ad Hitlerum)
  3. listen carefully and try to articulate the other position accurately
  4. show respect
  5. acknowledge that you understand why someone might hold that opinion
  6. try to show how changing facts does not necessarily mean changing worldviews.

The general answer is "don't try." As someone who passionately advocates science, I of course break this rule all the time.

The most important thing I have found to remember when trying to argue a pro-science position is that they've heard it all before. Science is currently accepted by a substantial majority of people, and many will violently defend their understanding of it. As such, you can be quite confident that this is not the first time they have heard the arguments. They have already had time to evolve responses. The ad homeniem attack of "They're just in it for the money" is an excellent example of the kinds of responses they have learned to use to shut down scientific arguments.

The second most important thing I have found is to make sure you have enough time and energy for the discussion you are about to engage in. Don't start a discussion that cannot amicably resolve in less than an hour unless you're confident that both of you have an hour to spend on the topic. Nothing is less effective for defending science than suddenly realizing half-way through an argument that you can't make a convincing point unless you teach them differential equations first and their math background stopped around Algebra I.

With both of those in mind, the approach I find most helpful is not to argue that science has a better approach than they do. That combative approach naturally walks into the "they've heard it all before" argument, because we've all learned the rote arguments which try to explain why science is good. Instead, I find it most effective to learn more about their beliefs. If they say "dogs aren't like people," start the discussion by probing into why they feel that statement is applicable to the current topic of getting medical tests done. It should be easy to identify ways that dogs indeed are like people. They have bones, and blood, and a brain. There are clearly parallels. It should also be easy to identify ways that they are different. Dogs have a tail, while our spine ends in a coccyx. Dogs have different cones on their retina than we do, so they see different colors.

Once these obvious parallels and obvious differences are agreed upon, then start exploring biology with them. Try to find regions where it's not so clear to them whether dogs and people are different. Seed proper skeptical doubt in their worldview. It's healthy! Once you're there, the interesting part begins. There's one of two processes that follow:

  • If you find something about dogs and people that is interesting to them, but which they have trouble pinning down as a parallel or a difference, suggest that science has an answer that is convenient for science, and work with them to come to a rationale for why they should agree with this particular answer. Maybe it's a question of whether the dog's nails are alive or dead. Maybe its a question of why a cattle dog acts the way it does. The question will be unique to this discussion (avoiding the "they've heard it all before" issue), and it's interesting to them. If you can convince them that science has a good idea, that's a rock from which you can later build arguments for the validity of accepted scientific positions, and you've built faith that science isn't such a bad idea.

  • The other possibility is that they find something interesting that you can't find a scientific argument for, one way or the other. This is far more exciting, because now you have to explore something as well! In these situations, I like to thank the individual for challenging my worldview and go play with those ideas. In general, I find people who reach this situation appreciate that I don't push them to accept some poorly thought out argument phrased in scientific jargon. They seem to like when I admit "this is not in the realm which science has an answer for." It builds credibility so that next time I claim there's a scientific answer to be had, they actually believe me.

In all, the general pattern I recommend is:

  • Try to find an obvious case where they are right, and an obvious case where they are wrong. Typically the case where they are right is provided by them, and the case where they are wrong is something which they felt was so obviously wrong that they didn't need to be specific in their wording (Of course all cats are alive, except for the ones that were dead. Yes, there are dead ones too. I just didn't think we needed to be that pedantic when talking about cats!)
  • Try to find a case which is in the grey region between them, encouraging them to be skeptical of the idea that there's a clear line between right and wrong here. (How do we draw the line between what makes a cat alive and what makes the cat dead?)
  • Help them find something in the grey region which interests them, then either:
    • Show them science's model of that thing, and help them develop their own argument that suggests that science has the right answer (at least in this one isolated case) (Old medicine argued one died when one's heart stopped. Modern medicine has shown that brain activity continues after this point, letting us save more people)
    • If science doesn't have a good model of the thing, openly admit it, and then go explore the topic yourself. You may learn something! (Are there situations where it is possible that we simply don't know if the cat is alive, and thus ressecutatable, or simply dead, no matter how much science we apply?)

There are some good practical answers here but I want to add something more theoretical to provide a way to view these kinds of situations. Disclaimer: I am a researcher in a science field.

The construction of one's beliefs relies on a number of presuppositions ("axioms"). These statements are not provable in a strict sense, they are just assumed to be true a priori. These foundational beliefs are rooted in the individual's life experiences, cultural traditions, a certainty in their utility ("its worked for me before"), habit, or as a means of gaurunteeing personal certainty in an uncertain world. In reality, we cannot have certainty that these beliefs are "true" absolutely, but we can have degrees of confidence depending on how well-defined the question is. The fact of the matter is that if you disagree with someone on these foundational beliefs, you will always end up talking past each other - if one person doesn't trust vets, for example, the rest of the conversation is mostly doomed from a scientific standpoint! This means that any effective strategy must involve questioning the presuppositions that are brought to the discussion.

In my opinion, for testable hypotheses, the scientific method is the best approach we have to creating models that reflect reality. It is the best way to building these foundational beliefs. Try to imagine just how different the world looks for someone who has never studied science before. Without a benchmark to measure uncertainty or the accuracy of predictions, people stick to what they know best or what has given them the best results even if these principles only work well locally or in limited situations. This means that you need to ultimately convince the other person that your particular set of presuppositions is more effective at modeling reality.

Having a productive conversation with someone with views so divergent from yours requires following this kind of conversation flow, which respects some of the ideas presented above.

  1. Inquire into why they hold a belief. Try to get them to question why they hold a particular foundational belief instead of asserting your belief in the matter. Ask about the context of when they formed this belief - was it something from their childhood? Was it because of a pivotal life event? This tactic is not meant to tell them they are wrong but to gently point out weaknesses in their position. Ideally, this should be done with just questions since they can, if phrased correctly, not come across as judgemental. Your questions should come from a place of curiosity and not because you want to undermine their stable worldview.
  2. Validate their viewpoint. In emotional situations, people often want to be validated and heard. If they feel heard they may be less defensive. Commiserate and say you understand how their experiences could have led to what they believe now. Remember that science, whether theoretical or applied, is not monolithic. Science has been misapplied, people have used it and made big mistakes, and it has been inaccurately portrayed by reporters and others. There are bad doctors, bad scientists, and bad people in this world. All this factors into how people may view where you come from. Even if the other person is likely wrong, you will get nowhere with them unless you at least acknowledge their viewpoint. If you are unwilling to do this, then I would say it is best not to have a conversation at all. Now that you have listened to them, they may be more willing to listen to you (even if they don't agree).
  3. Share your viewpoint. Explain your point of view and how your experiences with science (or other philosophical system) have given you certainty. Try to avoid saying that it is a better approach but perhaps mention examples of how it has provided a better answer to an alternative viewpoint. This may seem like you considered two options and picked the one with better explanatory power rather than vilifying someone/group of people for holding a view. If someone has been attacked this way before, they may assume this is your strategy even if you did not intend it.
  4. Continue to probe and provide more examples. Pick up the conversation again. Probe deeper with questions, provide more examples and slowly build your case over multiple conversations. Never try to tell them your viewpoint is better but just nudge them a little bit each time. With many people they will slowly start seeing things the way you do (even if they disagree) and, if you are lucky, may give a bit more ground each time you talk.

I have had tremendous success with this strategy in many areas (politics, religion, etc). However, you will have varying degrees of success with this strategy depending on the personality of the person. A "conspiracy theorist" type personality may attempt to undermine every statement you say ("but how do you know for sure the doctors aren't being paid to say that?" "what if those scientists are wrong?") which will make progress difficult. But for many people, you will find that they hold their beliefs because of an unverified fear, because abandoning it would mean abandoning their community, or because it is destabilizing the only mechanism they know that provides stability and certainty in an uncertain and dynamically changing world. Using the strategies above can help cut through this roadblock in some situations.


This is a particularly tricky question. "can you have a discussion with them?" has a very basic answer - it's not possible. It simply isn't possible to discuss science when another participant is discussing dogma. When basic principles (of both science and debate) are ignored in favour of 'the truth'. Your well researched and experienced opinion is never going to be able to compete. Simply put 'the truth' in such cases isn't something that can be argued with.

So how can you deal with situations like this without seeming to be rude or judgemental? I often resort to one or all of the following

  • "oh, I didn't know that"
  • "I couldn't really comment on it before I've read up on it"
  • "I'd be interested in seeing where you read that"

Or something similar. This givens them some measure of validation, or at least does not contradict their belief, yet allows the conversation to move on to another subject.

In fact I usually do read up about their point(s) afterwards. Usually just for my own amusement, as even if you found a good argument they'd already have some reason to disbelieve it eg. "they're only in it for the money".


Counter-intuitively, you should not use arguments that are clear, concise and easy to understand. You should address misconceptions and make the other person think.

Derek which is producing the Veritasium videos wrote his PhD thesis about teaching science, and talks about how he builds up his videos to counter the findings that "too easy to digest" information results in:

  1. Students think they know it.
  2. They don't pay their utmost attention.
  3. They don't recognize that what was presented differs from what they were already thinking.
  4. They don't learn a thing.
  5. They get more confident in the ideas they were thinking before.

The above advice is good - you can't change such peoples minds quickly, or easily, if at all.

But I gather the question is more about better approaches, since you wish to try (good!) And would like to do so to better effect.

On that score, I'm similar. The key, I think, is how good you are at finding the logical flaw "thinking on your feet". For example many people might think of a reply to "People aren't dogs!", but comparatively few can think of one that is both hard to rebut and also comes to mind in a couple of seconds "in the moment", as a strong reply. That's the real difficulty in an answer. There are good approaches but having them on hand isn't easy.

Mental rehearsal is good. Knowing from past experience, the common arguments in your field, makes it more likely you'll have them to hand when you want them.

Some good "generic" approaches might help as well (note that labels for these are my own for this question):

  • Be on the lookout for social and scientific generalisations, they are easy to respond to.

    Social generalisations are about categories of people ("All doctors? Every last one? That sounds like bias rather than reality, I don't actually think that's even remotely true") ("I think you'll find there are good and bad in every field. I seriously doubt that medical researchers are evil trolls who laugh when their useless medicines harm you.") ("Does that mean you think I don't care? If that's the case tell me now.").

    Scientific generalisations are about facts that one can research ("Vaccines harm everyone? Do you plan to tell the people who fought for Ebola vaccines or no longer suffer smallpox, or recovered from rabies, that you're sorry their vaccines were fakes, and please reject them and die?")

  • Look for clear contradictions. I recently had to point out to someone arguing their trade had a moral right to act an obnoxious way, that in fact he earned a LOT more then most people. This wasn't enough - he tried to argue this was "just recent", which I knew it wasn't, or it was somehow true relatively because his work was harder than many people. But spotting the self contradiction was key. Another example is a response something like "Police are all corrupt", and delicately enquiring if they found their child missing, who would they ask help from. Again some statements have very sharp self-contradictions. You usually have to argue a bit more because they won't let go easily or at all, and only grudgingly move on.

  • Appeal to expertise. ("No, people aren't dogs. But they share all but one part in a few million of DNA, body chemistry, brain wiring, anatomy, and most other things, and I think I would trust the word of researchers who study humans and animals for decades, when they say that for their research, dogs are so close to humans that what is true for one, gives a very good idea of what's true for another, much more than somebody who's never done a days research in their life into it.")

  • Appeal to commonality, which is similar. (Roughly like this: "Do you really think when a dog bleeds and a human bleeds, the bleeding mechanism and clotting mechanisms are very different? What about inflammation, do you somehow think dogs and humans differ much there? Did you even realise that many human mental health meds - antidepressants, anti-anxiety meds - work identically in dogs and humans, and that's despite the brain being the most complex and in some ways the most different organ we have? So yeah, when very human doctor says an Xray is best for this condition, damn right I'm going to take it seriously as a starting point at least, for what might help my dog, whether its based on human studies, dog studies, or some other kind of study that's taken seriously in the medical world.")

    (And in reply to the predictable followup "But dog and human blood cells differ!", something like this: "Yes they do. And thanks to scientists we know what differs, what's the same, and when we can usefully apply results from one of them to the other".)

  • Point out the obvious. This is a kind of self-contradiction. (Have they ever had antibiotics? Antiseptics? Any injury treated at a hospital? Did they refuse antibiotics and antiseptic treatments because "all doctors are corrupt and just want profit"? Would they tell someone with a heart attack to never call an ambulance because doctors of course can't be trusted? What about if they felt sick for a week, or a baby in their family was coughing non stop? Whatever they say, it's the same - Typical, the moment you need something, guess who you actually rely on. Did you ever check which antibiotics were tested on non humans, or which treatments included which tests, to refuse them because they 'clearly' don't really work? No you didn't. Did you ever look up phase III research to check your facts, like medical researchers do? No you didn't.")

You can't win, but you can hold your own with this ki d of thinking.

  • Thanks for the answer! I've actually used some of your counterarguments (e.g. polio and smallpox.) And I know they take their kids to the doctor. Some of your approaches, though, seem to me to be maybe too... confrontational. I don't want them to be defensive. Aug 29, 2017 at 19:46
  • Call it "challenging" instead. And yes. But that's down to personal.style I reckon :)
    – Stilez
    Aug 29, 2017 at 20:18

Generally what you are asking is how to open someone's thinking to be more receptive to what you have to say and this is a common issue on many topics. You are at a particularly disadvantageous position in this context though as you happen to represent for many whom you wish to sway the very thing they are arguing against. It might be very akin to a debate between someone very staunchly Democrat debating a Republican about social policy reform.

The only effective strategies I know in such cases is firstly, assume the person you are talking to has this view for very good reason. You have to actually believe this. If you do not, they will feel the lack of intellectual respect given and it causes a reactionary defensiveness of their position. If it helps, imagine that the person you are speaking to has experienced something significant in their own life that has caused a serious mistrust and care about what that is. If you can figure out what that things is (and believe me, there is nearly always something to this) then you can allow them space to talk about that. You can even ask empathetic questions (not ones meant to make a point, but ones meant to help you understand details of what went on) and then you might have an in. Now you have established you are not like all others. You listen. You actually are trying to sort what "went wrong". I know that doesn't inherently help with the immediate topic, but it's not that long of a process if you get used to this approach as people generally are really looking for someone from the "the system" who wants to hear where they have been harmed. I can tell you as someone who sought an answer to a medical issue for far to long, I know what it's like feel ignored, dismissed, blown off, talked down to, etc, and then you seek out anything alternative and what you get is responsive, caring, engaged people who absolutely want to listen and help. I am not saying they have the answers. I am saying they have a way of reacting that feels a lot more connective. So if you want to win someone over, connect. It is one of the only things I have seen work.

If you can manage to connect first, all conversation that follows about whatever specific topic, will be much more likely to be heard. Avoid anything that could come off as condescension or dismissive, even if what they say seems preposterous based on your knowledge. You have to treat it similarly to how you treat being a parent talking to teenagers about life. If you are too staunch and too much placing yourself as the "expert", you will send up walls where they see your information as something they cannot trust just like the rest of it. So just like a teen will discount what you say because clearly you grew up in the stone age and don't understand what they re even talking about, so people with mistrust of science/medicine will tell you that your education was hand selected for you. So they will accept that you believe it to be true, but also see you as potentially another "brain washed" victim of the medical establishment who was educated on "what they want you to believe". I hope that makes sense. I am finding it hard to articulate my reason for saying, connect. You can't win anyone over unless they have any reason to trust you and the best way to earn trust is to seem reasonable and you will seem far more reasonable after they feel heard.


One method I've found to be effective is to not convince them with your words, but with theirs. That is, the idea is to get them to come to your conclusions with their own reasoning. That way, they feel intellectual ownership of the idea, so in accepting it they are not just listening to you.

In general, this is difficult, but in this particular case I believe there is a simple way to achieve it. Start by acknowledging the validity of their idea that what applies to dogs does not necessarily apply to humans. Then you need to extend that idea far enough that they start to disagree with it. One possible logical extreme would be to say that what applies to one human does not necessarily apply to another human. Now, this statement is true but applying it too forcefully (in a manner of speaking) leads to clearly ridiculous conclusions. One might come to the conclusion that there is no reasonable way to test the effectiveness of medicine, since what works for one person might not work for another.

I'm not sure I would take the discussion to such extremes, but you could mention recent scientific issues like the idea that having too few female subjects in a clinical trial (or sometimes none!) might limit how much the results apply to women's health and not just men's. If you are lucky, they might start trying to arguing against you. If you are very lucky, they might even develop a coherent argument for why the results should generalize. The last step of the journey is then to get them to apply that reasoning to the original disagreement - ask why (or whether!) their argument does not apply to the 'dogs versus humans' case.

At this point, I should acknowledge that this is somewhat hypothetical. I've have not applied this idea in such a systematic way, so I can't say if it really works. In fact, in the worst case, it might even come off as manipulative. However, I believe the core idea is solid: if someone comes to a conclusion of their own volition, they are much more likely to believe it than otherwise.


The core of the problem is that most lay people, including those who do usually accept scientific results and are not advocates of anti-scientific conspiracy theories, have very little knowledge about the rigorous procedures used in science that leads to reliable results. Many people wrongly believe that it all comes down to the expertise of scientists when it's the peer review process and the verification that takes places when other scientists attempt to replicate the results and the subsequent reporting of such results in secondary review articles, that makes the system work.

While some lay people may know about peer review, they'll still tend to think that expert opinion is acceptable to some degree in scientific papers, they'll typically have no idea that literally any non-trivial statement has to be backed up with evidence or a citation has to be given. The whole point of this is then that tracing back some statement in a paper should never get you stuck at some paper where you just have to accept the author's expertise. When something really is based on opinion, it will always be described as such, never as a fact.

One can contrast this with the knowledge lay people have about the justice system. Why does John Doe accept that a convicted person is indeed guilty as charged? A lot comes down to the independent review of all the facts of the case, lay people know about this and they also appreciate that this review is extremely important, an appeal to authority by invoking the expertise of the police, detectives etc. would not work. While important, appeal to expertise alone is not good enough for an outcome to get universal acceptance.

The reason for this difference is caused by the way the media reports about science, one reports about some scientific finding, an expert is interviewed, so one can read about the actual facts, but the procedures like peer review are hidden from view. In contrast, a news report on a criminal case cannot escape reporting about the legal procedures.

One can see this stark difference in attitude in controversial legal cases where many people believe that an innocent person has been jailed. In such cases, the argument usually will be about whether or not the person in question should get a retrial. So, we're then not talking about just accepting the arguments of the person at face value, rather one is arguing for getting these arguments properly processed by the legal system. Contrast this with how climate skeptics make their point. They'll argue against the primary scientific arguments, they'll often cite blogs where counterarguments are made, but they never argue about, say, "wrongly rejected articles". To get their way, scientists would just have to accept the counterarguments of the skeptics at face value.

Now, it's of course impossible to explain how science works when you're already in a casual discussion with someone who doesn't accept some scientific fact. But it's still worthwhile to do this when the opportunity arises. E.g., when eating out with friends when the topic is how boring today's workday was, it's not a problem to mention that you need to revise a paper, that you find that boring work but that scientific rigor requires backing up everything.

If they get it in their heads today that scientists reading your paper expect to see verifiable evidence on literally anything, you may prevent one of them getting swayed by anti-scientific ideas tomorrow.


You need to keep in mind that scientists, or doctors, or other experts, do not always know best and are often in disagreement with each other.

Unfortunately, the presence of some poor studies and disagreeing experts means that, for many people, all studies and scientific claims become highly suspect. To some extent, skepticism is good, but where is the balancing point?

It is not uncommon for doctors to release contradictory - sometimes even mutually-exclusive - findings. It is even more common that a doctor tells you something that you "know" to be wrong. When this happens, it is only natural for skepticism to increase.

I can use myself as a good example. For almost my entire childhood, I ate a diet of almost exclusively carb-loaded foods. Throughout elementary and high school, it was normal for me to go weeks at a time eating nothing but grain-based foods, mostly Ramen noodles and elbows or ziti (plain and dry, no sauces, butter, or anything), often on bread as a sandwich (I would cook the Ramen, drain it, and put the noodles on bread). Plenty of people will tell you now all about how too many carbs is a problem, and supposedly a carb-heavy diet is bad for you. Yet I was one of the healthiest people I knew for a long time: always a good weight, alert, rarely got sick, etc.. Now that I am older, my diet changed to become more normal (more meat, vegetables, and other stuff), and after a few years of abandoning my carb-only diet, my health has been declining; I'm gaining more weight than ever, tired all the time, sick more often, etc..

How am I supposed to respond to all the people who provide me with expert knowledge, often from doctors, who insist that my previous diet that I held for 20+ years was bad for me?

I agree with you that it is frustrating when trying to debate, or even just discuss, with people who refuse to be reasonable. However, when it comes to health and medicine, a lot of "known good" and "known bad" things keep changing, doctors do disagree, and it appears from the outside that doctors are unreliable.

Another view to consider: Sometimes the data that we get from doctors is good but their interpretation of it is opinion-based or biased.

You mentioned "anti-vaxxers." That's me, my family, and a lot of my friends. We know the risks. We read the literature, and I cannot deny the statistics and the science, but I can deny the common myth that you need to be vaccinated or you are part of the problem.

There are plenty of ways to avoid catching or spreading a disease that are equally effective, or more, than vaccines. We generally practice the best form of disease control: we just keep to ourselves. My wife works at home, the kids are home-schooled, and I am the only person who regularly leaves the house (and I wouldn't either if I could avoid it). We have home sanitization procedures that we follow if any of us has been around many people or new people, or if we are concerned we could have been exposed to anything. Our procedures probably look paranoid to outside viewers, but I assure you that despite being among your "anti-vaxxers" we are less of a concern than your average "vaxxers."

Our kids are rarely ever sick, especially compared to their peers, and if they do get sick it is almost always because of some average, vaccinated friend or family member who caught something from school and passed it on to us because they were rude enough to be around people without mentioning they were sick.

Anyway, the moral of my second point here is that sometimes the people you talk to do not disagree with your science, but rather they disagree with the opinions that doctors have formed based on the science. For example, I do not disagree with the statistics you find about any particular disease, but I do disagree about the best way to defend against it, and I am willing to do my due diligence to follow through with my life choices. In the end, my family is less likely to contract any particular vaccine-preventable disease than any random other family that has been vaccinated.

Some of the people you talk to might be like me: educated and aware of the data you are likely to provide but uninterested in arguing the conclusion.

For those who simply do not like critical thinking, and there are plenty in that category, well, there's not much you can do there. I feel for your "But we are not dogs" response. I know a guy who eats almost exclusively meat and practically no plants, saying "Plants aren't food; plants are what food eats," and he insists plants are unhealthy. When I point out his bad health and also that the animals he eats were themselves healthy before he ate them, he dismisses me with "But we aren't cows." Granted, cows digest food differently, but that does not dismiss my point. People like this will find whatever scientific article supports their view (this goes back to the aforementioned "doctors disagree with each other"), and they will cling to it against all odds. There is little you can do about that.


My main points have been:

  1. Look to your own argument and make sure that it really is as common-sense as you think it is; maybe it's not. If it were, there wouldn't be some other scientist disagreeing with you. Answer: Try researching alternate views, even non-peer-reviewed ones. Peer reviewed does not mean correct.
  2. Maybe the other person is not disagreeing with your science but rather with your opinions that are drawn from the science. Answer: Try asking the person if they have any logical reason for their point of view. Warning: Many people hate this, and since this is interpersonal stackexchange maybe this is not the answer.
  3. Some people just cannot be reasoned with no matter what. Answer: Shake your head and walk away.
  • Thanks for the answer, and the food for thought. May I ask you a few questions? (Feel free to just answer, "No.) Have you considered that you're less healthy now because of your poor diet when you were young (young people can get away with a lot)? If you believe diet is responsible for your present condition, why not simply return to your high-carb diet? Aug 30, 2017 at 20:37
  • 1
    Yes, I have considered it, and I know that definitely is a possibility. I do not believe that my diet was the healthiest for me. I think my good sleeping habits, lots of exercise, and my drinking choices (I eschewed water, drinking O.J. and milk instead; no water=bad but it got me stuff I otherwise lacked) probably helped a lot, and I was healthy despite my Ramen+ziti-only. If diet were balanced then, I'd likely be even better. I was trying to answer from the skeptic's point of view about "Why could someone be like this and what do I do about it?" Someone could reasonably assume (1/2)
    – Aaron
    Aug 30, 2017 at 21:27
  • (2/2) that Ramen+ziti-only was good for them and the doctor was a quack because of their experience. I do not actually believe that in my case, but I could easily understand why someone might. I do, however, think that my no-vax lifestyle is healthier than a conventional-vaccine one. However, no-vax without any precautions could still be a problem (I am neither for nor against that preference).
    – Aaron
    Aug 30, 2017 at 21:30
  • @anongoodnurse Also, while I do not believe the exclusive Ramen+ziti diet was good, I do still think that the negatives of it are exaggerated. I believe that the diet was unhealthy, but not as unhealthy as other diets that exist today, such as the protein-only diet like the atkins diet. I eventually switched to wheat and whole-grain products which was an improvement but still was lacking. My diet growing up was not good, but rather that it was "not as bad as many other peoples'", which assists the "I'm healthier than you so my diet is good" illusion. -1 > -9, but -1 is still negative.
    – Aaron
    Aug 30, 2017 at 21:41
  • Skepticism, at least that gleaned from the logical Socratic or practical Humean forms, is a good thing. Well, Hume did tend to take the non-zetetic attitude a few times; Socrates, and his disciple Plato, seemed to know better in some ways. Anyways: From my experience, though, most people don't really know useful skepticism, and it is such a pseudo-skeptical response that you are describing, yes? Aug 30, 2017 at 23:56

First of all, you must answer yourself, do you want to be a preacher, persuading people out of sin, or have nice conversation with them. Teaching ex-cathedra won't help you to achieve the second. Adult people don't like to be preached by someone whose authority as a preacher they haven't accepted on their own. They have doubts, they want to discuss, they except someone else will be willing to discuss. Preacher is not willing to discuss anything, therefore is not a good partner for discussion.

Second, do you have doubt about the truth you believe? Science is about having doubt. All that scientific method can give us is to tell, which statement is more likely to be truth. No more, no less. Even the paradigma itself should be questioned. Without doubt, there's no progress, only stagnation.

Third, please accept, people really have reason to distrust science. Especially in health-related area scientists have messed up. Some because of naivety, some (probably) for financial reasons. When I was young and naively believed in anything that claimed to be scientific, there was a massive hate speech against animal fat. The butter was told to be almost poison, the margarine was told to be a magical cure. Now slowly people write, that the butter, eggs etc. are not so bad, actually quite healthy, and the real poison is the margarine (trans-fats). I was personally a victim of antibiotics-madness. As a child having applied this 'magical cure' a dozen times a year, which caused mayhem to my immunological system. From my personal experience, the best way to remain healthy is to avoid doctors if only possible.

The best way is to concentrate on positives. For example, if someone questions some therapy, say it was successful in so many cases that you believe it's a right thing to apply, because this is your personal experience. People may question theories behind that, but if you say, you're going to continue what is working for you, no person with sincere motivations can question that thing.

  • You make some interesting points. I don't usually start the conversations. I rarely tell people socially that I'm a doctor, but I don't lie if I'm asked what I do for a living. But you're right that if I have an attitude, no one will listen and with good reason. Aug 29, 2017 at 22:21
  • 1
    +1 for "really have reason". I am wondering, people here talk about "science" as there is some "universal scientific method". In fact, different disciplines employ vastly different level of rigor. And in many cases areas of science overlap, so a difference of opinions might occur. What if a person you preach to has a background in a different scientific area, which tells him that certain facts accepted in your science wouldn't pass a smell test if considered in his area? How would you deal with such person? Aug 30, 2017 at 4:52
  • @AliChen There is a theoretical idea of how science should be done but things become very complicated when one considers the practical, the complexity of the field under study, and the fact that a subjective mind still has to interpret what it means. The higher up you go (physics > chemistry > biology > psychology > sociology...) the more layers are stacked. Until all fields are formalized mathematically, it is difficult to be as rigorous. We must accept this shortcoming but state that the field does have some demonstrative predictive power and that's the best that can be done for now.
    – syntonicC
    Aug 30, 2017 at 16:13
  • Rather than tack on another answer, I will offer a comment here: Perhaps the “non-scientist” has nothing against systematic knowledge or logic, but against self-aggrandized scientists or scientism as an institution. Perhaps they don't know the difference. Are they actually anti-science or simply disenchanted? Et c. Aug 31, 2017 at 0:11
  • @syntonicC "The higher up you go (physics> chemistry> biology> psychology> sociology...) the more layers are stacked." Yes, except that the foundation layer is still Physics. More fuzzy layers are stacked on top of each other, but given the limited capacity of human brain, the layers become extremely thin, down to very rudimentary level. If the object of study is quite complex and spreads over several layers (like environmental sciences), it is easy to misunderstand fundamentals (due to lack of proper depth in education) and misapply them, and arrive to quite wrong results and conclusions. Aug 31, 2017 at 2:07

You can only really break the cycle by not doing it. They will always rise, so you must be the one to avoid provoking it if you're weary of the battle.

I hate to see the precise instrument of science being used in blunt ways by people around me, but I've come to appreciate that there is a value to them (placebo or psychosomatic) in letting them hold onto their beliefs, however inaccurate

Recent examples where I've started a debate that really degenerated:

  • them: "vitamin c is the only way to cure a cold"
  • me: "actually, your immune system is the only thing that will cure you of your cold"


  • them: "everyone would be far healthier eating my grandma's homemade soup than any crap you get in a can "
  • me: "not true; an allergy sufferer could be distinctly less healthy eating something with an unknown list of ingredients, as would an Olympic athlete with a finely balanced dietary regime"


  • them: "the sugar in fruit is much better for you than sugar in a packet because packet stuff is preprocessed and full of chemicals"
  • me: "everything is full of chemicals. Everything IS chemicals"

How could I have broken this cycle?

  • them: "vitamin c is the only way to cure a cold"
  • me: "yeah"


  • them: "everyone would be far healthier eating my grandma's homemade soup than any crap you get in a can "
  • me: "yeah"


  • them: "the sugar in fruit is much better for you than sugar in a packet because packet stuff is preprocessed and full of chemicals"
  • me: "yeah"

Don't feel bad; just come on stack exchange and spread the scientific wonders between your ears to people who actually want to receive it. Cecil Adams has been fighting ignorance since before I was born, and I don't think he's making much headway... Durn universe just keeps churning out better idiots! :)


Arguing is about winning the argument. What you're looking to do is not arguing but convincing. Convincing is not something that can be done easily if you're trying to convince someone who is already convinced of the opposite.

If you swap the positions, consider the chances that they will convince you of their point of view. It doesn't make a difference that you're right and they're wrong, and that the earth really isn't flat. They are convinced the earth is flat and thus they are right to call it flat and you are wrong to call it round.

If you want to go about convincing people, here are a two things to keep in mind:

  • Figure out what their belief is. In the case of the breeder, I got the impression their conviction was neither that the dog wasn't sick, nor was it that animal and human illnesses do not share similarities. I think their conviction was that western medicine is bogus. Imagine someone arguing with you about the placement of needles if you don't believe in acupuncture - that will not convince you that acupuncture works.
  • Give them time. Few to no people are convinced in the middle of an argument. But a few open minded people go home, think about it overnight, and have learned something by morning.

(please read the last lines as well)

I am uber-rational, PhD in Physics by education and atheist. Why people believe in religions has interested me for a long time, from the sociological perspective.

This interest started after a heated, few-months long discussion with a friend about religion. I was the "just think about this a moment and you will see that it is bonkers" guy (together with a heap of examples, counter examples, you name it). He was coming from a very religious family and the beliefs were passed on him.

After a few months he gave up and agreed that his faith did not make sense. I was proud of my contribution to the advancement of civilization and science.

He changed a lot, became less happy and ultimately got into a severe depression (he recovered, but it took some time). He had a bunch of problems but, from our discussions afterwards, it was clear that his rationalization (and abandon of religion) was a key reason (he had nothing against me, we are still very good friends).

This is to say that, sometimes, it is good not to let people think too much about philosophical aspects. I am perfectly fine with the fact that when I die it is over. A switch flipped and poof. Some people may be terrified if they do not have an afterlife to hold to. And this is fine.

This answer does not answer your question, it gives another perspective. Your question is about science and I strongly believe that in the ocean of complete stupidity we swim in, good science must be promoted. That people who may influence how our world is managed (voters?) should be enlightened, even if it does not work everytime. Specifically, the ones whose claims are dangerous (anti-vaxxers, cancer-treating herbologists or other similar yahoos) must have someone who will state another perspective (yes, the correct one). Otherwise their position will prevail.

So now to answer your question: choose your battles.

I do not care about someone who buys a 25 EUR homeopathic thing to cure a cold. It will be cured anyway.
I do care about the one who will use homeopathy to cure a real illness of his child.

I do not care about the mass at the church and people saying that "God will help us".
I do care when religion influences the physics school book or that they do not get an insurance because of the said help which ultimately fails to come.

Some things are just worth battling for, others not.

  • Thanks for this good answer. Interestingly, I am a Christian, and I came to believe because of my experiences in molecular biology, so I don't argue religion with anyone, either for or against, because, as you say, some people need it. I don't know what happens after death; it that's it, I'm still ok with it. As a scientist, I, too, care what's in textbooks, and science is one of the things I care deeply about. Genetics and evolution must be taught. Usually I'm not the one to start these conversations. I just don't know how or when to end them gracefully. (cont.) Sep 3, 2017 at 16:05
  • (cont.) I was faced with this situation just yesterday. I was having lunch with an old friend whose wife I had met for the first time. Well, it turned out she was a drug rep for a few years. Drug reps are people who arrange to promote their drug. They hold lunches, dinners, participate after hours at conferences, etc. The whole purpose is to get as many docs to write as many prescriptions for that drug as possible. Turns out, also, that she was a Big Pharma conspiracy theorist. She was right about some of it, but really, BP isn't holding back on "the" cure for cancer. And there's no convincing Sep 3, 2017 at 16:10
  • (cont) her that there is no single cure for cancer because not every cancer is the same. What cures leukemia won't necessarily cure breast cancer. But there is an insistence that they're holding on to the cure because there's money in chemo drugs, but not so much in the cure. My old friend was embarrassed when his wife started ("Here we go" he said), but she wouldn't drop it. How do I pick my battles there? How do I make an exit that doesn't imply, "I can't reason with you?", "You're just wrong," etc. I had to finish it with, "I don't know... I hope that's not the case." Sep 3, 2017 at 16:16
  • @anongoodnurse: after so many fights (I also was the local radio's "science guy") I ended such discussions completely. When it starts I say that I do not discuss these subjects anymore because i) we will not agree and ii) you will be offended by my opinions. When they insist I tell them that (when the subject is "science vs religion", a favorite of many) I strongly believe that a scientist who believes in a religion (cont)
    – WoJ
    Sep 3, 2017 at 16:54

This is only a partial answer, as it doesn't apply in all situations. But sometimes, difficulty arises because the person you are debating with feels that their whole world view is threatened. This can be the case if their beliefs come from religion, spiritualism, etc. You may hear something along the lines of "I just think there has to be something more to life" or "I don't think science has all the answers". At this point, reassurance is needed: you are not trying to argue with these beliefs. I find it very helpful in these conversations to take the angle that science is not "right or wrong", it is merely about making predictions, and these predictions may be "useful or not useful".

If someone does not "believe" in evolution, for example, and we can't convince them otherwise, the next best thing is to give examples where, if we assume evolution happens by natural selection, then it leads to useful predictions. E.g. making predictions about a newly discovered species, or predicting how antibiotic resistance will develop and spread in bacteria.

By framing the discussion in this way, although the essential content is the same, you are not making it a matter of "I'm right and you're wrong". You are simply defending the "usefulness" of science.


Understand that when you challenge my beliefs you are attacking my identity!

It is completely irrelevant if those beliefs are correct or incorrect, rational or irrational, or compatible or incompatible with other beliefs I may hold. If you challenge my beliefs then, emotionally, that is a personal attack on me.

Why we believe alternative facts

Much of the early research on motivated reasoning showed that people weigh facts differently when those facts are personally threatening.

As an educated person, you are actually more vulnerable, not less:

"It's almost as though the sophisticated approach to science gives people more tools to curate their own sense of reality," says Matthew Hornsey, PhD, a professor of psychology at the University of Queensland who studies the processes that influence people to accept or reject scientific messages.

Ju-jitsu Persuasion

... communicators must do a better job at identifying those roots and adjust their persuasion attempts accordingly (American Psychologist, in press). "This is what we call jiu jitsu persuasion: working with people's motivations rather than trying to fight against them," he says.

"The key question is not ‘Why do they disagree with the science?' but rather, ‘Why do they want to disagree with the science?'" Hornsey says. (my emphasis)

People communicating the facts often do so with the implication that the target is a bad person at worst, or uneducated at best, Campbell says. But an adversarial approach isn't likely to change minds.

That's a lesson cosmetics companies learned long ago: They figured out they'll sell more lipstick if they promise to enhance a woman's natural beauty rather than tell her she's ugly

  • Yeah, but are we interested in persuading people, and coming out on top, or are we seeking to better the common set of knowledge and comprehension? Aug 31, 2017 at 23:45
  • @can-ned_food sounds like a distinction with no difference
    – Dale M
    Sep 1, 2017 at 0:36
  • But this argument goes both ways. People struggling to get into academia... Usually required so much work of them that when they finally get in, they react as a personal attack for someone to question how science works ( or does not work ). The point is to make them think Are you telling me all that hard work was for nothing Sep 1, 2017 at 11:10

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