I imagine that quite a few people were upset by the title for this post, so let me explain what I mean, and please hear me out before you sharpen your pitchforks. The arguments used by all three of these groups, and indeed by science deniers more generally, are all fundamentally the same. In other words, the underlying logical structure is identical for the arguments used in support of all three of these positions. Thus, it is logically inconsistent to criticize one of these positions while embracing another.

You see, what I have observed over the past few years of blogging is that very few people like to think of themselves as “anti-science” or as a “science denier.” Those people certainly exist, and I do encounter them, but most of the people who visit my blog/page claim to love science…at least until it disagrees with their ideology. This puts them in a difficult position, because when a scientific result conflicts with their beliefs, they have to find some excuse or justification for why they don’t accept the results of science on that particular topic, and what I see over and over again is that everyone falls back on exactly the same excuses, regardless of what anti-science position they are trying to defend. For example, on several occasions, I have seen people criticize anti-vaccers for appealing to the authority of a few fringe “experts.” Then, a few threads later, I see those same people appealing to the authority of a few fringe experts on topics like climate change and GMOs. Similarly, I see people ridicule climate change deniers for thinking that all climatologists have been bought off, but when the topic shifts to GMOs, suddenly those same people start claiming that Monsanto has bought off all of the world’s genetic engineers/food scientists. Do you see what I am getting it? You can’t criticize someone for using a particular line of reasoning, then turn around and use that same line of reasoning to support your own particular form of science denial. That’s not logically consistent, and it’s not how science operates. Science is a method. It either works or it doesn’t, and you can’t cherry-pick when to accept it.

I suspect that people are becoming more upset with me, rather than less upset, so if you are currently unhappy with me, then I want you to stop and carefully think about this before you read any further. I’m not attacking you, I’m not even ridiculing you, but I am trying to help you think rationally and consistently. If you truly love science, rather than simply liking it when it agrees with your preconceptions, then you should hear me out. You should take a good look at the arguments and examples that I am going to present, and you should make sure that you are actually being rational and logically consistent. I also want to clarify that I don’t think people who believe these views are unintelligent or even consciously denying science. As I’ve previously discussed, I used to be a creationist and a climate change denier, so I know first-hand just how easy it is for ideology to cloud your judgment and make you think that you are being rational, when you are actually just denying reality.



It’s not about the evidence

Before I go any further, I need to make it explicitly clear that none of these positions exist because of any actual scientific evidence supporting them. In every case, they are soundly defeated by a veritable mountain of consistent scientific results. On GMOs, for example, over 1,700 studies have been conducted, and they failed to find any evidence that GMOs are worse than traditional crops for either human health or the environment, and in some cases, they are better (Nicolia et al. 2013; also see Sanvido et al. 2006, Snell et al. 2012, Van Eenennaam and Young. 2014, and the National Academies of Sciences, Engineering, Medicine report 2016). This is, of course, also the conclusion that nearly 300 scientific organizations reached after reviewing the data.

Climate change is the same story. Because of carbon isotopes, we know that we have greatly increased the CO 2 in the atmosphere (Bohm et al. 2002; Ghosh and Brand 2003; Wei et al. 2009), and thanks to satellite measurements, we know that our CO 2 is increasing the amount of heat energy that the earth’s atmosphere traps (Harries et al. 2001; Griggs and Harries 2007). Further, studies of past climate clearly show that CO 2 is a major driver of climate change (Lorius et al. 1990; Tripati et al. 2009; Shakun et al. 2012), and we have carefully studied the sun, volcanic emissions, Milankovitch cycles, etc. and none of them can explain the current warming, but including our greenhouse gasses in the analyses does explain the warming (Stott et al. 2001; Meehl, et al. 2004; Allen et al. 2006; Wild et al. 2007; Lockwood and Frohlich 2007, 2008; Lean and Rind 2008; Foster and Rahmstorf 2011; Imbers et al. 2014). Indeed, literally thousands of studies have all converged on the conclusion that we are causing the planet to warm, and peer-reviewed studies to the contrary are virtually non-existent (but see the next major point below). As a result, this is another topic that enjoys an extremely strong consensus among actual experts.

Similarly, vaccines have been studied thousands of times and have been shown to be extremely safe and effective. Indeed, they are the most well-studied treatment in medical history, and you can find trials that looked at pretty much whatever particular adverse event you are interested in. There are, for example, numerous studies that failed to find any evidence that vaccines cause autism, including a meta-analysis with over 1.2 million children (Taylor et al. 2014). There are studies showing that vaccines don’t cause SIDs (Hoffman et al. 1987; Griffin et al. 1988; Mitchell et al. 1995; Fleming et al. 2001; Vennemann et al. 2007a; Vennemann et al. 2007b), studies showing that they don’t cause asthma or allergies (Schmitz et al. 2011; Grabenhenrich et al. 2014), studies showing that the flu vaccine doesn’t increase fetal or infant deaths (Mak et al. 2008; Pasternak et al. 2012a; Pasternak et al. 2012b; Fell et al. 2012; Haberg et al. 2013), etc. (you can find a non-exhaustive list of a bunch of other safety trials here).

My point here is simple: all of these topics have been extremely well studied, and they are as close to settled as science ever comes. Anyone who holds one of these positions is denying a massive body of evidence, which is why I am comfortable with calling them science deniers. This also creates the dilemma that I will focus the rest of the post on. Namely, most of the people who hold these positions don’t want to be considered science deniers, so they have to come up with some excuse for rejecting science, and interestingly, they all seem to have converged on the same excuses.

Note: Inevitably on these topics, when faced with thousands of studies, people start shifting the goal posts and going down ever narrowing side-tangents, but the reality is that these topics are so well studied, that even if you want to go down a ridiculously specific side topic, in the majority of cases, there are still studies on that. So, before you comment with something to the effect of, “but what about…” or “the real issue is…” check and make sure that it hasn’t been studied, because odds are that it has.

Cherry-picking small, poorly conducted studies

In an attempt to counter these mountains of evidence, many people rely on cherry-picking a handful of studies that appear to support their position, but this is problematic for a number of reasons. First, these topics have been studied so many times, that it is almost inevitable that there will be a handful of studies that reached a false conclusion just by chance (even if the studies were conducted flawlessly). This is a simple by-product of the statistical tests that we use (details here). Further, it is blatantly obvious that not all studies are equal. Bad research does sometimes get published. So, whenever you approach a scientific topic, you always have to look for a consensus among studies, rather than just cherry-picking the ones that agree with you. This is why systematic reviews and meta-analyses (like the ones that I cited earlier) are so useful. They condense the results of many papers into a single work so that you can see the overarching trends, rather than being deceived by the statistical outliers.

Additionally, you need to critically examine a study before you accept it. Ask yourself questions like, did it have a large sample size? Was it controlled properly? Did it use a robust design? Did it use the appropriate statistical tests? Was it published in a reputable journal? etc. These are really important questions, and they are questions that anti-vaccers, climate change deniers, and GMO opponents rarely ask. Indeed, these positions are famous for citing truly horrible studies. Just in the past few weeks, for example, anti-vax websites were singing the praises of a “new” study that claimed to show that vaccines were harmful, but in reality, the study was not set up correctly, it did not use the correct analyses, and it was so terrible that it was quickly retracted (details here). Further, that is far from a one-off event. Sherri Tenpenny (one of the leaders of the anti-vaccine movement) created an online “library” that exists for the express purpose of cherry-picking anti-vaccine studies for you; that way you can just see the studies that agree with you, without having to be bothered with the mountain of high quality studies that disagree with you (details here). Indeed, she makes no attempt to hide the fact that her site exists to help you find information that confirms your biases rather than trying to figure out what is true. For example, one of her pages advertising her site says (the weird capitalization was in the original),

“Convinced that Vaccines are Unsafe but Need Scientific Proof? You need information that gives you ‘The Other Side of the Story.’”

Similarly, on the topic of autism, anti-vaccers eagerly share lists of 100+ papers that supposedly show that vaccines cause autism, but as I explained at length here, many of those papers aren’t on autism or aren’t on vaccines, and the ones that are on topic all used small samples sizes and weak designs that can’t establish causation. In contrast, there are several large cross-section and cohort studies and even a meta-analysis with over 1.2 million children, all of which consistently failed to find any evidence that vaccines cause autism.

It’s easy to poke fun at anti-vaxxers for this, but climate change deniers and GMO opponents are no better. They do exactly the same thing. For example, I still see anti-GMO activists citing Seralini’s infamous rat study that claimed that GMOs caused cancer in rats. You’ve almost certainly seen it at some point next to pictures of grotesque looking rats. If you look a bit closer though, you’ll see that they used a breed of rats that already has high cancer rates, and the cancer rates of the GMO-fed rats were within the expected rates for that breed. As with so many of these fringe papers, that one has been retracted for being awful, but GMO opponents have plenty of other small and equally terrible studies, some of which I have discussed here. I also recommend this study which showed that many of those anti-GMO studies failed to use the correct statistics (they didn’t control the type 1 error rate), and when you apply the correct methods, the evidence that GMOs are dangerous disappears (Panchin and Tuzhikov 2016).

Climate change denial is the same thing, but I think I’ve made my point by now, so I won’t dwell on it for long. I would, however, encourage you to read the following critique on many of the climate change denial papers (Benestad et al. 2017; the supplemental information is particularly useful). As you might have guessed, they found that the studies were riddled with problems, and their results couldn’t be replicated.

Appealing to a minority of fringe “experts”/inflating the conflict

Appealing to authority is another common tactic among all pseudo-science positions. All of these positions have a list of “experts” who they cite as evidence that their position is legitimate (Dr. Tenpenny and Dr. Mercola for vaccines, Dr. Soon and Dr. Spencer for climate change, Dr. Seralini for GMOs, etc.). After all, if someone has an MD or PhD they must know what they are talking about, right? Wrong! Earning an advanced degree does not guarantee that you are smart, nor does it guarantee that you know what you are talking about. So the fact that you found some MDs/PhDs who agree with you does not in any way shape or form validate or legitimize your position. Further, if we are going to insist on appealing to authority, why on earth should I listen to a cherry-picked handful of scientists instead of the vast majority who disagree with them? Additionally, in many cases, the “experts” being cited don’t have any relevant qualifications. Dr. Tenpenny, for example, is an osteopath. That hardly qualifies her as vaccine expert. Similarly, climate change deniers love to tout the “Oregon petition,” which is a fraudulent list of over 30,000 “scientists” who signed a petition saying that climate change isn’t real (because that’s how science works, we sign petitions on what is and is not a fact [sarcasm]). When you actually look at the signatures, however, it quickly becomes clear that most of the people on the list don’t have degrees in a field that is even remotely close to climatology, many of them aren’t scientists at all, and only around 0.3% were actually climatologists.

All of this is closely related to a logical fallacy known as an inflation of conflict. It occurs when you use a minority of experts to falsely claim that there is serious debate about a topic that is actually pretty well settled among experts. The classic news interview with one climate change denier vs Bill Nye is a great example of this. It makes it look like two even sides, when in reality, it should be one climate change denier vs. over 30 climatologists (yes, there is roughly a 97% consensus in both the literature and among climatologists; multiple studies have converged on that number). This same strategy of inflating the conflict is also at play when people cherry-pick a handful of papers while ignoring the majority of papers that disagree with them (see point above).

Finally, inflation of conflict fallacies also frequently occur when people present a minor disagreement as if it is a major one. For example, I frequently see people present the fact that climatologists and climate models disagree about the exact extent of warming that will occur as evidence that there is general disagreement about climate change, but that is totally false. Virtually everyone (and more importantly, all of the data) agrees that the planet is warming, we are causing it, and it will create problems. Similarly, people often take disagreements over precise safety levels or specific facets of GMOs and vaccines and act as if there is widespread disagreement about their general safety.

Inventing conspiracy theories

So, if cherry-picking papers and experts won’t work, then what is a science denier to do? Obviously, you invent a conspiracy. After all, why should you believe all of the studies/experts that say you are wrong when you can dismiss all of them in one fell swoop by blindly claiming that they were all paid off as part of some massive cover-up.

That may sound crazy (and it is) but it is exactly what people do all the time. When I present papers to science deniers, whether they are anti-vaccers, climate change deniers, anti-GMO advocates, homeopaths, etc. they almost always respond by blindly asserting that the study was funded by “Big Pharma,” Monsanto, etc. That response is not, however, logically valid. You can’t just assume that a paper is biased simply because you don’t like it. Further, scientific publications require authors to declare their conflicts of interest, so you can actually check and see if the paper was funded by a source that might have biased it. When you do that, you find that there are tons of independent studies that were conducted by researchers who aren’t affiliated with companies and didn’t receive funding from them. On the topic of vaccines and autism, for example, I have previously shown that most of the papers that confirmed the safety of vaccines did not have a conflict of interest, and many of the low-quality anti-vaccine studies did have conflicts of interest. Similarly, roughly half of GMO safety trials are conducted by independent scientists. I don’t have exact numbers for climate change papers, but if you start looking at the funding sources as you will find that quite a few of them are independent as well (I talked more about the money trail for all three of these positions here).

When faced with this fact, people almost invariably go down the conspiracy route and insist that all the world’s climatologists, doctors, etc. are being paid off. This is, however, 100% an assumption. Indeed, it is what is technically known as an ad hoc fallacy. It is a logically invalid excuse that I would never accept unless I was already convinced of the position being defended. You cannot just invent conspiracy theories to get around the fact that thousands of studies demonstrate that you’re wrong.

Nevertheless, some people try to make their position sound more legitimate by claiming that it’s not actually a conspiracy, but scientists are just going along with it to get grant money. That doesn’t make sense, however, because grant agencies usually rely on a board of scientists to review applications. So, for this to work, you’d have to have every scientist in a given field agreeing to give money to crap projects just to keep the money flowing for everyone, which means that we are back to a conspiracy (also see the point below). Further, this claim is, once again, an assumption. You can’t state an assumption as if it is a fact, and you can’t use an assumption as an argument. Ask yourself this, is there any reason to think that this type of wide-spread corruption is happening, other than an ideological desire to reject these studies? No, there isn’t. There is no evidence whatsoever to support this baseless assumption.

Falsely claiming that scientists are going with the dogma of their fields

If being a conspiracy theorist doesn’t suit you, you might try claiming that many scientists actually know that climate change isn’t caused by us, GMOs are dangerous, etc., but they can’t go against the “dogma of their fields” because they’ll be ridiculed, won’t get funding, etc. That is, however, simply not how science works. In fact, it is the exact opposite of how it works. If this claim was true, then science would never progress, because no one would ever question the status quo, but science does progress because we constantly question the status quo. Indeed, challenging the accepted wisdom of our fields is the job description of a scientist. That’s what we do. No one is going to give you funding to test something that everyone already knows. You get funding for new and innovative ideas, for pushing boundaries, and for questioning what we think is true.

I’ve said this before, but it is worth saying again: every great scientist was great precisely because they discredited the common views of their day. As a scientist, just going along with the “dogma” of your field guarantees that you will have an unremarkable career and history will quickly forget you. If you want to get the big grants and go down in the history books, then you need to start discrediting some common views. Indeed, for me personally, as a young biologist, nothing could possibly be better for my career than discrediting evolution. It would win me a Nobel price and my choice of universities to work at, and the same thing would be true for a young climatologist who discredited climate change, an immunologist who demonstrated that vaccines do more harm than good, etc. So, why aren’t eager young graduate students publishing these revolutionary data? Because those data don’t exist! Extraordinary claims require extraordinary evidence, and if you want to overthrow a common view, you are going to need some really solid evidence, and there simply is no extraordinary evidence to support positions like climate change denial.

Finally, this argument is an assumption, and you cannot use an assumption as evidence. Unless you can actually prove that scientists are doing this, you simply don’t have an argument.

Note: To be clear, I’m not suggesting that one study would change things overnight. Scientists are a critical bunch, and we would want several labs to confirm a major finding before we overturned our fields, but being one of the scientists involved in that overturn would guarantee you a place in the history books. As a result, any scientists would be crazy to sit on those data and not publish them.

Relying on secondary sources (blogs, Youtube videos, etc.)

At this point, we have exhausted anything even approaching a legitimate line of evidence or reasoning, but don’t worry, there’s always the internet. I’ll keep this one brief: if you want to claim that a massive body of scientific evidence is wrong, then you have to argue against it using the peer-reviewed literature. Nothing else will suffice. Nevertheless, anti-vaccers, GMO opponents, and climate change deniers all love to direct people to blogs, videos, etc. as evidence that their position is correct.

Appeal to anecdotes, personal experience, etc.

In keeping with the point above, anecdotes, isolated news reports, personal experiences, etc. simply don’t matter. I, quite frankly, do not care if you feel healthier when you don’t eat GMOs, observed an adverse event after a vaccine, don’t think it feels warmer now than it did in the past, etc. Science says you’re wrong (well, more specifically, scientific studies provide evidence showing that you’re wrong, since science itself is a method, but I digress). As I said above, for scientific topics, only scientific studies count as evidence. You simply cannot use an anecdote as evidence against a study.

General cherry-picking

I’ve talked about several specific cases of cherry-picking throughout this post, but it is probably worth mentioning that this is also employed as a more general strategy. In other words, people will cherry-pick isolated facts or instances and totally ignore the big picture. For example, anti-vaccers love to cite particular instances when a vaccine failed or when a problem was detected, while totally ignoring all of the times that they worked wonderfully and saved millions of lives. Similarly, anti-GMO activists will cite particular cases where a GMO hybridized with a wild plant or a pesticide had some negative effect on the environment, while totally ignoring all of the times that these things didn’t happen with GMOs or did happen with traditional crops. Yes, traditional crops (including organic) can be quite harmful for the environment as well. They can kill non-target species, damage the soil, hybridize with wild plants, etc. Indeed, when you look at the big picture, GMOs actually have fewer and less-severe impacts on the environment than traditional crops (see the sources in the first section, and also realize that I am necessarily speaking in crude generalities for the sake of writing a post rather than a book; there are lots of traditional crops and lots of GMOs and some are better than others, so I am talking about a general average effect, but it’s really better to compare two specific crops). Climate change deniers, of course, do exactly the same thing. They delight in pointing to blizzards or the Antarctic Sea ice, while totally ignoring the mean temperatures, heat waves, receding glaciers globally, etc.

Appealing to nature

This one is admittedly a bit more of a mixed bag. Anti-vaccers and GMO opponents do this very blatantly by claiming that vaccines/genetic engineering are bad because they are unnatural (which of course is a logical fallacy, because the fact that something is natural tells you absolutely nothing about whether or not it is good), but climate change deniers have their own form of appealing to nature as well. This occurs when they make the baseless and logically invalid assertion that the climate has changed naturally in the past, therefore the current warming is natural (see the sources in the first section for why we know it isn’t natural).

Again, for this one, the climate change denial argument is admittedly a bit different from the anti-vaccine/anti-GMO argument, but it is similar enough that I thought it was worth mentioning, and, indeed, I frequently see climate change deniers argue that global warming isn’t a problem because it is natural (which is a proper appeal to nature fallacy).

Claiming that science is flawed/science has been wrong in the past

When backed into a corner by the evidence, even those who claim to love science will frequently resort to some variation of the “science has been wrong in the past/they laughed at Galileo and Columbus/science said the earth was flat” argument. I’ve dealt with this argument several times before (here, here, and here), so I’ll be brief.

First, of course science has been wrong before. That’s how it works. It is a gradual process of testing ideas and replacing old ones with new, better ones. If science was never wrong, science would never advance. This brings me to the second point: every time that a scientific result has been shown to be wrong, it was discredited by scientists doing science, not by someone on Youtube, a personal anecdote, etc. As I have said several times now in this post, for scientific topics, you must present evidence from peer-reviewed studies.

Third, most of the common examples of science being wrong (e.g., a flat earth) pre-date modern science by quite a bit. Indeed, it is really hard to come up with an example in the modern era where something as well established as climate change, GMOs, or vaccines has been discredited. Oh sure, there have been plenty of times when a popular idea was debunked, but none of those had the literally thousands of studies that these three topics have (no, the idea that smoking was safe was never strongly supported by scientific evidence). About the best example you can come up with is Einstein’s theory of relativity replacing Newtonian physics, but that wasn’t really a replacement as much as an expansion (i.e., Newtonian physics still work under most circumstances, they just weren’t complete).

Finally, the fact that science has been wrong before does not in any way justify your particular brand of science denial. Again, you need actual evidence. Also, if you accept science on some topics, then you are being logically inconsistent. In other words, if you can use the fact that science has been wrong before as an argument against climate change, for example, then why can’t I use it as an argument against gravity or against the shape of the earth?

But science is never settled/I’m just asking questions

Finally, many people like to appeal to the inherent uncertainty that is built into science and claim that the fact that science is never truly “settled” somehow justifies their denial of the current body of evidence. Or, they might claim to be “just asking questions” or “asking for more studies.”

That sounds fine at first, but it is actually just disguised denialism, and here’s why. It is technically true that science is never “settled” in that any result can technically be overturned by future evidence. In other words, science tells us what is most likely true given the current evidence, not what is absolutely true. However, that does not mean that it is valid to reject the current evidence whenever you want to. For example, it is technically possible that we are wrong about gravity, but it would be crazy to assert that since science is never settled, I am justified in rejecting the concept of gravity. Even so, topics like vaccines, GMOs, and climate change (I’ll throw evolution in there as well) have been so thoroughly studied that it is extraordinarily unlikely that we are wrong about them. To put all of this another way, it is logically invalid to assume that the current evidence is wrong just because it technically might be wrong (that is an argument from ignorance fallacy). You have to provide actual scientific evidence that it is wrong, otherwise you are not adhering to the rules of logic.

Similarly, there is nothing wrong with asking questions. In fact, I encourage it, but, you have to use good sources to answer those questions, and you have to be willing to accept the answers. In other words, there is nothing wrong with someone who has never studied climate change asking questions like, “is there good evidence that we are causing it?” but, when they are presented with the mountain of studies that clearly show that we are causing it, at that point, they can no longer claim ignorance. If you continue to act like the evidence isn’t there after you have been shown the evidence then you are, by definition, a denier. The same thing is true for those who claim to just want additional studies. The reality is that these topics have been so thoroughly studied from so many angles that if the current evidence can’t convince you, then nothing will. If the current evidence isn’t enough for you, then the problem isn’t the evidence, the problem is your adherence to ideology.

Summary

As I have tried to demonstrate throughout this post, climate change denial, the anti-vaccine movement, the anti-GMO movement, and pseudoscientific positions in general are all fundamentally the same. They all ignore a large body of evidence while citing a few, cherry-picked, low-quality studies. Further, they all try to cast doubt on that evidence by appealing to a minority of “experts,” and they all invent baseless conspiracy theories and accuse scientists of blindly following the dogma of their fields. When you get right down to it, all of these positions are based on ideology, not facts. Again, to be clear, I am not attacking or even criticizing anyone. Rather, this is a plea for rational thought. A large portion of my readers seem to fully embrace the science on at least one of these topics, while rejecting the science on the other(s), but that is logically inconsistent. You can’t, for example, criticize an anti-vaccer for ignoring studies and inventing conspiracies, then turn around and ignore studies and invent conspiracy theories about climate science or GMOs. As I’ve said before, science is a method. It either works or it doesn’t, and you can’t cherry-pick when you do and do not want to accept the results that it gives.

Note: Inevitably someone is going to comment with something like, “I accept that GMOs are safe for humans and the environment, but I oppose them because food shouldn’t be patented, Monsanto is evil, etc.” (similar arguments exist for the other topics as well). If you are thinking about writing a comment like that, please don’t. If you truly fully accept the science, then for the sake of this post, I don’t have a problem with you. Most of those arguments do have countless logical inconsistencies and I think they are absurd, but for the sake of a post about denying the science itself, I don’t feel like discussing them here.

Note: Someone may be tempted to accuse me of a fallacy fallacy. This occurs when you say that a position is wrong because of the arguments that are used to support it (i.e., it happens when you reject the conclusion of a bad argument, rather than rejecting the argument itself). That is not, however, what I am doing. Climate change denial, GMO opposition, etc. are wrong because of the mountain of scientific evidence showing that they are wrong. So I am not saying that they are wrong because of the bad arguments. Rather, I am simply trying to explain why the arguments are bad.

Literature cited