Antivaccine nonsense Autism Medicine Science Skepticism/critical thinking

Motivated reasoning and the anti-vaccine movement

One theme that I keep revisiting again and again is not so much a question of the science behind medical therapies (although certainly I do discuss that issue arguably more than any other) but rather a question of why. Why is it that so many people cling so tenaciously to pseudoscience, quackery, and, frequently, conspiracy theories used by believers to justify why various pseudoscience and quackery are rejected by mainstream science and medicine? Certainly, I’ve touched on this issue before on several occasions, for example, with respect to the anti-vaccine movement, the claim that abortion causes breast cancer, and how we as humans crave certainty.

It turns out that science and science-based medicine are hard for humans to accept because they often conflict with what our senses perceive, which our brains then interpret as irrefutable evidence. The pattern-seeking function of our brain, when evaluating questions of causation in medicine, frequently betrays us. For instance, when a parent sees her child regress into autism sometime not long after being vaccinated, the easiest, most instinctive, and most emotionally compelling conclusion is that the vaccine must have had something to do with it. When scientists tell her that, no, in large studies looking at hundreds of thousands of children, there is no good evidence that vaccination confers an increased risk of autism and a lot of evidence that it does not, it’s a very hard message to believe, because it goes against how the parent interprets what she’s seen with her own eyes. Indeed, how often have we seen believers in the vaccine-autism link pour derision on the concept that when something like autistic regression happens in close temporal proximity to vaccination that the correlation does not necessarily equal causation? “Coincidence?” they will spit. “I don’t believe it.” Similarly, believers in “alternative medicine” who experience improvement in their symptoms also pour derision on the observation, explained so well by R. Barker Bausell in Snake Oil Science, that people frequently take remedies when their symptoms are at their worst, leading them to attribute natural regression to the mean to whatever nostrum they started taking at the time.

These issues have come to the fore again, thanks to an article by a former ScienceBlogger, Chris Mooney. The article appeared in a recent issue of Mother Jones and was entitled, rather ironically, The Science of Why We Don’t Believe Science. Chris made his name as an author primarily in writing about the science of anthropogenic global warming and the political battles over policies intended to mitigate it and, to a lesser extent, over creationism and evolution denial. Of late he has written about the anti-vaccine movement as an anti-science movement, leading predictably to his being attacked by the likes of J.B. Handley. Also of note, although he was widely praised for The Republican War on Science and Storm World, more recently Mooney has been widely criticized for being too critical of “new atheists” and for lack of substance. In his current article, he discusses some of the science thus far about why people can cling to beliefs that science doesn’t just cast doubt upon but shows convincingly are totally wrong.

Motivated reasoning

In his article, Mooney sets the stage with a very famous example studied by Stanford University psychologist Leon Festinger in the 1050s of the Seekers. The Seekers were an apocalyptic cult in the Chicago area led by a Dianetics enthusiast named Dorothy Martin. Its members believed that they were communicating with aliens, one of whom was named “Sananda,” who was supposedly the astral incarnation of Jesus Christ. Martin also taught her followers that Sananda had told her the precise date of a world-ending cataclysm: December 21, 1954. As a result, some of Martin’s followers quit their jobs and sold their homes because they expected that a spaceship would rescue them right before the earth split open and the sea swallowed much of the United states. In fact, Martin’s followers even went so far as to rid themselves of all traces of metal, even removing underwire bras and taking the zippers out of their clothes, because they were told that such metal would pose a danger to the spaceships. Here’s Mooney’s account of what happened when December 21, 1954 came and went and, as those of us living today know, no cataclysm occurred:

At first, the group struggled for an explanation. But then rationalization set in. A new message arrived, announcing that they’d all been spared at the last minute. Festinger summarized the extraterrestrials’ new pronouncement: “The little group, sitting all night long, had spread so much light that God had saved the world from destruction.” Their willingness to believe in the prophecy had saved Earth from the prophecy!

From that day forward, the Seekers, previously shy of the press and indifferent toward evangelizing, began to proselytize. “Their sense of urgency was enormous,” wrote Festinger. The devastation of all they had believed had made them even more certain of their beliefs.

In the annals of denial, it doesn’t get much more extreme than the Seekers. They lost their jobs, the press mocked them, and there were efforts to keep them away from impressionable young minds. But while Martin’s space cult might lie at on the far end of the spectrum of human self-delusion, there’s plenty to go around. And since Festinger’s day, an array of new discoveries in psychology and neuroscience has further demonstrated how our preexisting beliefs, far more than any new facts, can skew our thoughts and even color what we consider our most dispassionate and logical conclusions. This tendency toward so-called “motivated reasoning” helps explain why we find groups so polarized over matters where the evidence is so unequivocal: climate change, vaccines, “death panels,” the birthplace and religion of the president (PDF), and much else. It would seem that expecting people to be convinced by the facts flies in the face of, you know, the facts.

I’ve actually written about motivated reasoning before a couple of years ago. At the time, I used a then-recent study that examined how impervious to evidence certain beliefs about politics were, specifically the belief that Saddam Hussein had been involved in planning 9/11, conspiring with Al Qaeda to destroy the World Trade Center twin towers. In this study, even President George W. Bush’s own words stating that Hussein was not involved in planning 9/11 were not enough to convince believers. Another study cited used similar methodology regarding Saddam Hussein’s lack of weapons of mass destruction. In fact, in this study, there was a “backfire” effect, in which those exposed to disconfirmatory information about Saddam Hussein’s involvement with 9/11 were actually more likely to believe that he was, in fact, involved. Also discussed was the belief that President Barack Obama was not born in the United States and is therefore not eligible to be President (the “Birther” movement, which recently suffered a bit of a setback) and the belief that there were “death panels” written into the recently passed Patient Protection and Affordable Care Act. In the study I discussed, the authors based their analysis of motivated reasoning on its being driven primarily by cognitive dissonance, the the feeling we have when we are forced to become aware that we are holding two contradictory thoughts at the same time. The strength of the dissonance depends upon the importance of the subject to an individual, how sharply the dissonant thoughts conflict, and how much the conflict can be rationalized away, and cognitive dissonance theory thus posits that, when faced with evidence or occurrences that challenge their beliefs, people will tend to minimize the dissonance any way they can without giving up those beliefs.

To the list of examples provided by the authors, I also added the example of someone well-known to this blog, namely Andrew Wakefield, the (in)famous British gastroenterologist who in 1998 published a study in The Lancet that claimed to find a link between the MMR vaccine and “autistic enterocolitis.” When revelations of Wakefield’s financial fraud came to light, however, his fans in the anti-vaccine movement were motivated to cling all the more tightly to him, circling the wagons and attacking anyone who had the temerity to point out his fraud, bad science, bad medicine, and massive conflicts of interest. For example, just last month, in response to criticism of Andrew Wakefield, J.B. Handley, the founder of the anti-vaccine group Generation Rescue, pointed out that people like him view Andrew Wakefield as “Nelson Mandela and Jesus Christ rolled up into one,” an assertion I couldn’t help but comment on, likening the anti-vaccine movement to a religion. Never mind that, scientifically speaking, Wakefield is just as discredited in his science as Dorothy Martin was in her predictions of global destruction. In the same article, anti-vaccine activist Michelle Guppy warned the reporter direly, “Be nice to him, or we will hurt you.” As you can see, despite the drip, drip, drip of allegations and evidence showing Andrew Wakefield to be a horrible scientist and even a research fraud have not had much of an effect on committed activists. I would argue, however, that they did have a significant effect on the media and the fence-sitters.

For the most part, most scientifically literate people know what cognitive dissonance is, but what is “motivated reasoning”? According to Mooney, to understand motivated reasoning, you first have to understand that what we humans call “reasoning” is not a cold, emotionless, Mr. Spock-like process. The way we human beings reason is actually suffused with emotion, or affect:

Not only are the two inseparable, but our positive or negative feelings about people, things, and ideas arise much more rapidly than our conscious thoughts, in a matter of milliseconds–fast enough to detect with an EEG device, but long before we’re aware of it. That shouldn’t be surprising: Evolution required us to react very quickly to stimuli in our environment. It’s a “basic human survival skill,” explains political scientist Arthur Lupia of the University of Michigan. We push threatening information away; we pull friendly information close. We apply fight-or-flight reflexes not only to predators, but to data itself.

We’re not driven only by emotions, of course–we also reason, deliberate. But reasoning comes later, works slower–and even then, it doesn’t take place in an emotional vacuum. Rather, our quick-fire emotions can set us on a course of thinking that’s highly biased, especially on topics we care a great deal about.

As a result, if this hypothesis is accurate, it can be expected that people will almost always respond to scientific or technical evidence in a way that justifies their preexisting beliefs. Examples of evidence that support this hypothesis are listed, including the study I discussed two years ago using the example of the persistent belief that Saddam Hussein had a hand in engineering 9/11. Also discussed was a classic study from 1979 in which pro- and anti-death penalty advocates were exposed to two fake studies, one supporting and one refuting the hypothesis that the death penalty deters violent crime. In addition, they were also shown detailed scientific critiques of each study that indicated that neither study was methodologically stronger than the other. In each case, advocates were more likely to find the study that supported their bias more convincing and to be more critical of the one that did not.

To anyone who understands human nature, this is not particularly surprising. After all, as Simon & Garfunkel sang in their 1970 song The Boxer (one of my all time favorite songs), “a man hears what he wants to hear and disregards the rest.” That’s not quite motivated reasoning, but close. Motivated reasoning would be more along the lines of saying, “a man pays attention to information that supports his beliefs and values and finds ways to disregard or discount the rest.” This principle, more than anything else, probably explains why believers in alt-med and anti-vaccine activists are immune to disconfirming evidence. Not just immune, either, they actively seek out confirming evidence and avoid disconfirming evidence, a task made much easier by the Internet and multiple different news outlets catering to different ideologies:

Okay, so people gravitate toward information that confirms what they believe, and they select sources that deliver it. Same as it ever was, right? Maybe, but the problem is arguably growing more acute, given the way we now consume information–through the Facebook links of friends, or tweets that lack nuance or context, or “narrowcast” and often highly ideological media that have relatively small, like-minded audiences. Those basic human survival skills of ours, says Michigan’s Arthur Lupia, are “not well-adapted to our information age.”

We see this in the CAM movement. An entire network of websites and blogs has sprouted up over the last decade or so. CAM believers, if they wish, can peruse sites like,, and, watch television shows like The Dr. Oz Show, and never see a single piece of information or study that challenges their world view that because it’s natural it must be better, that conventional, scientific medicine is hopelessly in the thrall of big pharma, and that modalities that are nothing more than magical thinking can cure disease. Similarly, anti-vaccine activists have their own set of websites, including Generation Rescue, Age of Autism, the NVIC, the Orwellian-named International Medical Council on Vaccination (formerly “Medical Voices,” and discussed by Mark Crislip), SafeMinds, and many others. These CAM and anti-vaccine sites also have their own scientific-seeming meetings, such as Autism One (which, by the way, is fast approaching again) and the AANP.

Wrapped safely in such a cocoon, believers seldom encounter arguments against their cherished beliefs, much less strong arguments against them. No wonder they’re often so poor at defending their favorite woo when they dare to stray out of the safe confines of their little world. However, one interpretation of motivated reasoning that I’ve come up with states that you don’t actually have to be good at producing arguments that convince other people; you just have to be good enough to cherry pick arguments that convince yourself.

Politics, CAM, and the anti-vaccine movement

While Mooney’s summary for the evidence for motivated reasoning is compelling, he stumbles a bit in trying to ascribe different forms of motivated reasoning to the right and the left. While it is clear that certain forms of anti-science do tend to cluster either on the right or the left (for example, anthropogenic global warming denialism is definitely far more common on the right), if motivated reasoning is a valid hypothesis that describes well how human beings react to information that challenges their belief systems and values matter more (at least initially) than facts and science, then it would only be expected that certain forms of science would be viewed more hostilely by the right than the left while other scientific findings would be viewed more hostilely by the left. Unfortunately, one of the examples Mooney picks is fairly dubious:

So is there a case study of science denial that largely occupies the political left? Yes: the claim that childhood vaccines are causing an epidemic of autism. Its most famous proponents are an environmentalist (Robert F. Kennedy Jr.) and numerous Hollywood celebrities (most notably Jenny McCarthy and Jim Carrey). The Huffington Post gives a very large megaphone to denialists. And Seth Mnookin, author of the new book The Panic Virus, notes that if you want to find vaccine deniers, all you need to do is go hang out at Whole Foods.

It’s hard not to note right here that the founder of Whole Foods, John Mackey, is an anti-union Libertarian and admirer of Ayn Rand. In any case, I really hate it when people like Mooney try to pin anti-vaccine views as being mainly “on the left.” True, left-leaning crunchy types are the primary face of anti-vaccine views, but there is an entire underground on the right that is virulently anti-vaccine. These include General Bert Stubblebine III‘s Natural Solutions Foundation, far right libertarians, and others who want to protect their “purity of essence.” In addition, FOX News isn’t above pushing anti-vaccine nonsense. For example, of late the FOX and Friends crew has been doing sympathetic pieces on Andrew Wakefield, interviews with Dr. Bob Sears, SafeMinds’ anti-vaccine PSA campaign, Louise Kuo Habakus (who is virulently anti-vaccine herself and politically active in New Jersey pushing for transparent “philosophical exemption” laws. Politically, some of the most rabid anti-vaccine activists in government are conservative, for instance Representative Dan Burton. Moreover, conservative fundamentalist religion is not uncommonly a motivation for anti-vaccine views. Not surprisingly, Mooney’s example ignited a rather intense debate in the blogosophere, which included Mike the Mad Biologist, Razib Khan, Joshua Rosenau, Andrew Sullivan, David Frum, and Kevin Drum, among others.

This debate didn’t go very far in either direction because there aren’t actually a lot of good data examining whether there is a correlation between political affiliation and anti-vaccine views. Ultimately, Mooney followed up with a post on his blog in which he did the best he could do with polling data on the politics of vaccine resistance. Reanalyzing a poll from 2009 asking about Jenny McCarthy’s anti-vaccine views, specifically how many people were aware of them and how many were more or less likely to agree with them, Brendan Nyhan and Chris Mooney found:

So here are the results: Liberals (41% not aware, 38 % aware but not more likely, 21 % aware and more likely); Moderates (48% not aware, 28% aware but not more likely, 24% aware and more likely); Conservatives (49% not aware, 28 % aware but not more likely, 23% aware and more likely).

These results basically suggest that there’s little or no political divide in terms of who falls for Jenny McCarthy’s misinformation. Notably, liberals were somewhat more aware of her claims and yet, nevertheless, were least likely to listen to them. But not by a huge margin or anything.

Mooney also noted another poll done by Pew regarding whether vaccines should be mandatory:

What’s interesting here is that Pew also provided a political breakdown of the results, and there was simply no difference between Democrats and Republicans. 71% of members of both parties said childhood vaccinations should be required, while 26% of Republicans and 27% of Democrats said parents should decide. (Independents were slightly worse: 67% said vaccinations should be required, while 30% favored parental choice.)

Bottom line: There’s no evidence here to suggest that vaccine denial (and specifically, believing that childhood vaccines cause autism) is a distinctly left wing or liberal phenomenon. However, I will reiterate that we don’t really have good surveys at this point that are clearly designed to get at this question.

Even though the evidence is admittedly weak and more studies and surveys would definitely be in order, Mooney’s conclusion is nonetheless in line with my experience. I’ve said before many times that anti-vaccine views are the woo that knows no political boundaries. Although I don’t have hard scientific data to support this my contention and therefore can’t definitively discount the possibility that my observations represent confirmation bias, I’ve noticed that right wing anti-vaccine activists tent to be suspicious of the government and appeal to “health freedom” as a reason for their resistance to vaccination, and tend to eschew any societal obligation to contribute to herd immunity. Left wing anti-vaccine activists tend to be suspicious of big pharma and believe that vaccines are somehow “unnatural.” I realize my interpretation might be biased, but until better data are available it’s all I have to work with. Similarly, alternative medicine use tends not to fall into an easy left-right dichotomy either. My favorite example to illustrate this point is that, even though alternative medicine is viewed as a crunchy, “New Age” phenomenon more prevalent on the left, the Nazi regime actively promoted naturopathy and various other “volkish” alternative medicine modalities. I trust that now someone will invoke Godwin’s law, but forgive me; I was intentionally using an extreme example to illustrate my point that all parts of the political spectrum can be prone to quackery.

Finally, Mooney makes another point that I quibble with:

Well, according to Charles Taber and Milton Lodge of Stony Brook, one insidious aspect of motivated reasoning is that political sophisticates are prone to be more biased than those who know less about the issues. “People who have a dislike of some policy–for example, abortion–if they’re unsophisticated they can just reject it out of hand,” says Lodge. “But if they’re sophisticated, they can go one step further and start coming up with counterarguments.” These individuals are just as emotionally driven and biased as the rest of us, but they’re able to generate more and better reasons to explain why they’re right–and so their minds become harder to change.

I would quibble somewhat with whether, in the case of science and medicine at least, that apparent “sophisticated” understanding of the issues possessed by ideologues is actually as sophisticated as it appears on the surface. In some cases it might be, but far more often it’s a superficial understanding that has little depth, mainly because few lay people have the detailed scientific and medical background to apply the information. It’s often a matter of knowing facts, but not having the scientific experience, understanding of mechanisms, or sophistication to put them in context or to apply them to the situation properly. Thus, the arguments of, for instance, anti-vaccine advocates often have the veneer of scientific sophistication, but to those knowledgeable about vaccines are easily identified as utter poppycock. Examples abound, and include this “review” article by a man named David Thrower is, and every “scientific review” published by, for example, Age of Autism.

I can’t remember how many times that, while “debating” in, I would have a study quoted to me as supporting an antivaccination or other alternative medicine viewpoint and find that, when I actually took the trouble to look up the study and download the PDF of the actual article rather than just reading the abstract (which is all most lay people have access to and therefore all they read), I would find a far more nuanced and reasonable point or even that the article didn’t support what the altie was saying. One other aspect that often comes into play is an extreme distrust of conventional medicine and/or the government such that few individual studies that question the safety of vaccines are given far more weight in their minds than the many more studies that show vaccines to be extraordinarily safe or large metanalyses. Certainly this is one reason why the infamous Wakefield study, despite being shoddily designed and now thoroughly discredited, keeps rearing its ugly head again and again and continues to be cited by antivaccination activists as strong evidence that the MMR vaccine causes autism. Basically, what is happening here is that highly intelligent and motivated people can construct arguments that seem better to the uninformed.

One thing that must be remembered about motivated reasoning is that we as skeptics and supporters of science-based medicine must remember that, as human beings, we are by no means immune to this effect. Indeed, as Mooney points out, citing recent research, it’s quite possible that reasoning is a better tool for winning arguments than it is for finding the truth, and when motivated reasoning combine with the echo chamber effect of modern social groups bound together by the Internet and like-minded media, the result can be disastrous for science:

But individuals-or, groups that are very like minded-may go off the rails when using reasoning. The confirmation bias, which makes us so good at seeing evidence to support our views, also leads us to ignore contrary evidence. Motivated reasoning, which lets us quickly pull together the arguments and views that support what we already believe, makes us impervious to changing our minds. And groups where everyone agrees are known to become more extreme in their views after “deliberating”-this is the problem with much of the blogosphere.

Actually, I’m constantly asking myself when I’m writing one of these logorrheic gems of analytic brilliance if I really am being analytically brilliant or am I being selectively analytically brilliant in order to bolster my pre-existing beliefs and values? In other words, am I doing from the other viewpoint the same things that anti-vaccine zealots, for example, do when they cherry pick and misrepresent studies in order to support their beliefs that vaccines cause autism? Of course, that’s where our readers come in, as does the fact that I (and, I have no doubt, every other SBM blogger) frequently ask myself that very question. As Richard Feynman famously said, “The first principle is that you must not fool yourself – and you are the easiest person to fool.” Science is simply a method for minimizing the chance that you will fool yourself. To say “I saw it with my own eyes” is not enough, but that is what our brains are hard-wired to believe.

That’s one reason why I’m far less concerned about winning over committed ideologues. Although such a task is possible and people do change their minds, sometimes even about things very important to them, for the most part expecting to win over someone like J.B. Handley, Jenny McCarthy, or Barbara Loe Fisher is a fool’s errand. The people who need to be educated are the ones who are either on the fence or otherwise susceptible to pseudoskeptical, sophisticated-sounding arguments from denialists because they do not understand science or the issues. Although it will by no means be easy, such a goal is at least achievable.

By Orac

Orac is the nom de blog of a humble surgeon/scientist who has an ego just big enough to delude himself that someone, somewhere might actually give a rodent's posterior about his copious verbal meanderings, but just barely small enough to admit to himself that few probably will. That surgeon is otherwise known as David Gorski.

That this particular surgeon has chosen his nom de blog based on a rather cranky and arrogant computer shaped like a clear box of blinking lights that he originally encountered when he became a fan of a 35 year old British SF television show whose special effects were renowned for their BBC/Doctor Who-style low budget look, but whose stories nonetheless resulted in some of the best, most innovative science fiction ever televised, should tell you nearly all that you need to know about Orac. (That, and the length of the preceding sentence.)

DISCLAIMER:: The various written meanderings here are the opinions of Orac and Orac alone, written on his own time. They should never be construed as representing the opinions of any other person or entity, especially Orac's cancer center, department of surgery, medical school, or university. Also note that Orac is nonpartisan; he is more than willing to criticize the statements of anyone, regardless of of political leanings, if that anyone advocates pseudoscience or quackery. Finally, medical commentary is not to be construed in any way as medical advice.

To contact Orac: [email protected]

54 replies on “Motivated reasoning and the anti-vaccine movement”

Motivated Reasoning as the lever to move those entrenched and inconvenient facts. Nice presentation Orac. A good reference piece.

I had my students read Mooney’s article and this one:

They wrote 3-5 pages on the main points and their thoughts on the main points. It was quite enlightening to see the spectrum of responses which ranged from taking offense to someone challenging their faith to fanboyism. Interestingly, there was no clear cut relationship between academic achievement and location on that spectrum.

A fine piece, thanks — and thanks for invoking that great Feynman piece on Cargo Cult Science.

One minor typo — just under the bold head for “Motivated Reasoning” you place the Seekers in the 1050s rather than the 1950s, which threw me for a moment.

To make up for the nitpicking, I’ll direct any interested readers who haven’t seen it to The Onion’s insole piece, one of the finest satires of quackery ever:,759/

If you think Wakefield was bad look at this woo from Weibel et. al. In this junk science paper he says the MMR causes, “mental regression and retardation, chronic seizures, motor and sensory deficits, and movement disorders (kinda sounds like autism to me)and death”. We need to demand that Pediatrics retracks this paper now.

Pediatrics. 1998 Mar;101(3 Pt 1):383-7.

Acute encephalopathy followed by permanent brain injury or death associated with further attenuated measles vaccines: a review of claims submitted to the National Vaccine Injury Compensation Program.

Weibel RE, Caserta V, Benor DE, Evans G.

Source Division of Vaccine Injury Compensation, National Vaccine Injury Compensation Program, Health Resources and Services Administration, Public Health Service, Rockville, Maryland 20857, USA.

RESULTS: A total of 48 children, ages 10 to 49 months, met the inclusion criteria after receiving measles vaccine, alone or in combination. Eight children died, and the remainder had mental regression and retardation, chronic seizures, motor and sensory deficits, and movement disorders. The onset of neurologic signs or symptoms occurred with a nonrandom, statistically significant distribution of cases on days 8 and 9. No cases were identified after the administration of monovalent mumps or rubella vaccine.

CONCLUSIONS: This clustering suggests that a causal relationship between measles vaccine and encephalopathy may exist as a rare complication of measles immunization

This is off topic but it is well worth bringing to attention. Marc Siegel has always been a horse’s ass but this is really getting ugly. I got this press release in my e-mail:


– Mind-Body Control The Key Says Dr. Marc Siegel – Prayer And Faith Can Help

In a new thought provoking, sure to be controversial book, Dr. Marc Siegel, Associate Professor of Medicine at the New York University School of Medicine and a Fox News Senior Correspondent says that cancer, heart disease and even death can be prevented by people understanding and recognizing their “inner pulse.”

The just released book, The Inner Pulse, explores the mysterious connection between body, mind, and spirit in the health and healing process.

“You don’t have to get sick, don’t have to die and can rise out of your wheelchair to walk again. Prayer counts, meditation matters, exercise is crucial, and understanding your inner pulse can allow you to master your body, and defeat many illnesses which modern doctors will tell you are uncureable,” says Siegel. “You can defy the odds by learning to know your inner pulse and responding to what it tells you. Disprove anyone who would write you off too soon.”

Dr. Marc Siegel is the author of several acclaimed books on the effect of pandemic viruses and how to prepare for them; his latest, The Inner Pulse, explores the mysterious connection between body, mind, and spirit in the health and healing process. Dr. Siegel is an Associate Professor of Medicine at the New York University School of Medicine, the Founder and Medical Director of Doctor Radio and a columnist for the Los Angeles Times and USA Today.


Diana Lombardi


[email protected]

Fox News is exactly where he belongs.

Excellent post!

Basically, what is happening here is that highly intelligent and motivated people can construct arguments that seem better to the uninformed.

I see this frequently with some* of the engineers that I work with. They are very intelligent and very confident and make very bold and convincing arguments. If you are not familiar with the topic, their rationals sound very logical. However, if you challenge them with a decent argument you can typically discover that they are really just making stuff up and are more concerned about demonstrating that they are right than with the actual reality.

*I’m not bashing all engineers. Most do not do this. However, because of the intelligence and education required to become an engineer, the one’s that do it can be very convincing.

It’s very infrequently I read much online content, but I found your article very informative and interesting from the start. You mention good points and keep things interesting. Thank you.

Similarly, believers in “alternative medicine” who experience improvement in their symptoms also pour derision on the observation, explained so well by R. Barker Bausell in Snake Oil Science, that people frequently take remedies when their symptoms are at their worst, leading them to attribute natural regression to the mean to whatever nostrum they started taking at the time.

There’s also the Kahneman and Tversky study of Israeli Air Force instructors, where the instructors’ experience convinced them yelling at trainees was the most effective teaching method. K&T showed it was simply a case of regression toward the mean.

If a trainee did better than usual and was praised, the tendency to regress toward the mean of the trainee’s performance meant he would likely do worse next time. Conversely, if a trainee did worse than usual and was yelled at, the tendency to regress toward the mean meant the trainee would likely perform better next time. Thus the trainers mistook correlation (yelling correlated with improved performance in the next session) for causation, and the simple mathematics of regression toward the mean meant the trainers would receive constant reinforcement of their mistaken view.

And you’ve pointed out in past posts how regression toward the mean leads to a constant stream of surprising drug trials or study results, followed by a consistent failure of the promising early results to pan out over time and/or with larger groups.

Although I don’t have hard scientific data to support my contention and therefore can’t definitively discount the possibility that my observations represent confirmation bias….

A bit ironic considering the subject of your post, eh? 🙂

Forgot to mention a wonderful example of motivated reasoning from a comment on another blog. The comment took the news of Bin Laden’s assassination as confirmation that Obama was a secret Muslim terrorist, because only a Muslim would be so concerned that Bin Laden receive burial in accordance with the tenets of Islam.

Another devastating and fascinating piece. Where do you find the time?!

I was particularly interested in your point that anti-vaccine views are not directly linked to political persuasion.

I’ve heard it said regularly in recent months that vaccine scepticism is the preserve of sandle-wearing, organic-eating, hybrid-driving, lefties. But it seems equally as common among anti-government libertarians.

However, when it comes to other issues where science is close to consensus – like the influence of mankind on climate change – the green/left-leaning liberals side with the science while the hard right clings to the minority view.

Meanwhile, other conservatively-minded people tend to trust their government, doctors and scientists on vaccines but have a blind spot for climate science.

So, as you suggest, there’s no simple, consistent relationship between politics and trust in science. Whether you accept what scientists say comes down to a whole set of complex beliefs. This allows people to take inconsistent positions on the value scientific evidence, depending on the issue.

Alas, this only makes it harder to reach people if your aim is to improve vaccination rates.

Angie, again missing the disconnect between “rare complication” and “autism epidemic”.

Mu,”mental regression and retardation, chronic seizures, motor and sensory deficits, and movement disorders”. This is what autism looks like in today’s children. The study out from Yale today say’s it now affects 1 in 38. This does not fit the description of rare. Where is the alarm!

Coming as I do from the social sciences, I tend to look at this in two steps: we have a cognitive system that works in a particular way ( attention, memory, learning, problem solving) which we can understand and even “game” (i.e. make it do as we want ) which takes place in a social context of language and communication with others which we study.

I look at Orac’s question ( in the next to last paragraph) in a slightly different way: of course, we are doing the *same* and yes, we’re *susceptible* to the same influences and *can* fool ourselves rather easily. However, this idea haunts our thought much as the concept of error is inherent in statistical tests: we are- to various degrees- *looking for it*. We attempt to trip ourselves up and self-critique ourselves. I could go on and on on recursive thought, meta-cognition, execution function, formal operations, and suchlike.

I would prefer to look differentialy across a spectrum of ability to self-evaluate. When we address the “true believers” of anti-vax there are frequently other isssues at hand: they can be distraught parents dealing with a difficult situation which can worsen their ability to question their own beliefs and prime face-saving attribution to external causation. The lost often seek an inspiring leader to lead them out of their own personal wilderness.

I had a thought about what I experience when I read some pseudo-scientific literature: it reads like free association, stream-of-consciousness writing. It hinges upon semantic connections rather than logical or fact-based connections. Our woo-meisters’ polemics invoke strong emotional contra-indications to criticisms of either the writer or the reader’s reaction. They project absolute confidence in their ideas and discourage questioning.

I counsel people and also manage money for myself and others: in both “careers”, I am often deluged by a flood of information that is ephemeral, contradictory, ambiguous, highly emotional, and uncertain. I often can’t tell what is “real” or what is a strong influence or trend I must follow closely. It ain’t easy- it could drive you to drink**: so far it hasn’t.

** opium’s too dangerous.

You’ve conflated two things.
1. There are known complications that can come from the MMR vaccine in a small number of people under certain circumstances.
2. A recent study in a town in South Korea found that approximately 1:38 children showed up somewhere on the autism spectrum. Many of these children had not been previously identified as such and were considered to be “normal” and “doing well in school” though they had some social issues.
So far, there is no demonstrated link between the two.

The 1:38 is also a single study at this point. It should be taken with a shakerful of salt until/unless similar figures are replicated by other research groups in other populations.

If Mooney could just get his facts straight on the new atheist I would agree with just about everything he says.

@ Angie: Where did you get that (deliberately?) edited Pediatrics Journal abstract from?

Another permutation of that same (deliberately?) edited abstract was posted by “Polly” on Orac’s blog “Progress mixed with in personalized medicine” (May 2nd).

I provided Polly with the unedited abstract at:

Pubmed 9481001

I also provided other data that was (deliberately?) omitted from Polly’s posting including the fact that under the “Methods” section of the (deliberately?) edited abstract was the fact that the study analyzed 48 cases of serious neurological events following measles vaccination OVER THE COURSE OF 23 YEARS; doing simple math we arrived at two cases per year over the study period of 23 years.

Angie, you have (deliberately?) omitted what “qualified” these 48 children to be part of the study…which was that they each experienced a severe neurological event within 15 days of having received a measles vaccine and that no further qualifications were listed. Indeed no mention was made in the real abstract if these 48 youngsters had a history of developmental delays or seizures or if they were diagnosed with a serious viral or bacterial illness or if they were diagnosed with a genetic disorder.

As a replied to Polly in my posting @ #19 on the blog, please provide us with your source for the (deliberately?) edited abstract and that there is no need to thank me for the correct Pubmed citation…or for correcting the obviously (deliberately?) edited abstract.


While I was pecking away at the keyboard responding to Angie and providing the real abstract, Polly decides to come out of hiding and posts.

Okay, Angie and Polly…please provide us with your source(s) for the bogus abstracts. And, where is the indignity you must both feel if you didn’t doing the “editing” and were innocent in the whole matter?

I would quibble somewhat with whether, in the case of science and medicine at least, that apparent “sophisticated” understanding of the issues possessed by ideologues is actually as sophisticated as it appears on the surface.

I think the idea was not so much that the “sophisticates” have a deeper understanding of the issues (or the science), but are better at spinning the issues in their favor.

By the way, a great way to employ motivational reasoning is to attack the (perceived) motivations of your opponents.

Polly, slowly and in extra large crayon:
48 cases in 23 years (with millions of MMR shots) is extremely rare.
Autism Spectrum Disorders (whether you take the 1% or the 2.5% number) are widespread.
Even if all 48 cases are examples of MMR caused autism, that doesn’t tell us anything about the million other cases we’re trying to find a cause for, as clearly proven by autism in unvaccinated kids (clue English pharmasist’s “there are no unvaccinated kids with autism!” next).

For the record, the “new atheist” objection to Chris Mooney isn’t that he’s “too critical” so much as that he’s “grossly intellectually dishonest and shamelessly pandering in his criticism of ‘new atheists.'”

Great post, but I do have to quibble one point: “the belief that Saddam Hussein had been involved in planning 9/11, conspiring with Al Qaeda to destroy the World Trade Center twin towers (the “9/11 Truth” movement)”

The 9/11 Truth movement is generally understood as a conspiracy theory that presumes some degree of US government foreknowledge or even active involvement. See the wiki article of anything related to the execrable “Loose Change” video. There is not much overlap between Truthers and the believers in Hussein’s involvement, aside from an affinity for counterfactuals.

Name the 1st world nation with the highest number of vaccinations (and recommended vaccinations) before age 2. That same country (U.S.) also has the highest infant mortality rate. Hmm…

Aaron @25

Name the only 1st world nation without universal public health insurance. That same country (U.S.) also has the highest infant mortality rate. Hmm…


@ Aaron:

You might want to check out the detailed takedown Orac’s “friend” did of why that’s utterly wrong. Simply put, the ACTUAL reason is that the US uses a different definition of infant mortality. And the authors had to go to a great deal of trouble in order to get their desired conclusion even with that.

@ Todd W: I located the press release from Yale at:

Talk about a skewed study! 55,000 records of children ages 7-12 were reviewed including records of special education children, children listed on a disability registry and records of children enrolled in general school programs. The press release states:

“The method unmasked cases that could have gone unnoticed…Two thirds of the ASD cases were found in the mainstream school population, unrecognized and untreated”.

The press release then discusses the Korean education system and the rigors of 12 hour education days and then draws the “conclusion” that such structure may not allow for the diagnose of ASD. That was my doh moment!

In rare instances where very subtle learning deficits, developmental lags, behavioral problems or difficulties interacting with others are not picked up on by parents or doctors prior to entry into nursery school or kindergarden…the “rigors” (5 hour school days) of our educational system here in the United States, picks up on these youngsters at age 6 in first grade.

I’m sure this “landmark” study will be featured on such websites as Huffington Post, Age of Autism, etc., with analyses by the usual suspects.

Polly, psychiatric diagnoses can be iffy things. I should know, I’ve had a few. Case in point:

Mephistopheles O’Brien

Many of these children had not been previously identified as such and were considered to be “normal” and “doing well in school” though they had some social issues.

That sounds a lot like me and my twin brother. Depending on which evaluation you read, we’ve been everything from completely normal to ADD to having Asperger’s syndrome. Some psychologists appear to stick diagnostic labels to kids more than others. “Social issues?” On my dad’s side of the family, just about everyone starts out shying away from contact even with immediate family – sometimes to the point of hiding in the forest for days to avoid talking. Eventually, we outgrow it. Mostly. Autism, or just shy nerds? Depending who you ask, you can get seemingly any diagnosis. And if diagnosis can vary all the way from 100% normal to off the deep end of Asperger’s syndrome, the incidence figures must be similarly all over the map.

So no, I have no confidence in claims that there’s a growing autism epidemic. It could be better diagnosis (less false -s), or worse diagnosis (more false +s), or broader diagnosis(-s reclassed +s), or just the latest fad among new psych. grads (more false +s).

So if the diagnostic criteria were changed (they did change) and there were more psych students graduating with poorer quality control in graduates, and continuing autism research improved the ability of the good grads to recognise autism, but it also became a hot topic in the media and therefore a diagnostic fad, I’d expect to see all of the above.


My thoughts were that, if the study is replicated anywhere, what implications does that have for how we define ASDs? Is the definition too broad?

Because I feel adrift in a slippery world of shifting opinions, ideas, and trends that wave like fronds of kelp subjected to the currents of the sea, stable ground can usually be found in externally verifiable data by that stand up to repeated scrunity. In other words: before I buy or sell anything, I fact-check multiple independent sources: you can’t expect this to come from *within* yourself.

There’s a huge difference between saying 1 in 38 kids have some symptoms of autism and saying 1 in 38 kids meet the full criteria for autistic disorder. What this study seems to demonstrate is that when you broaden the criteria for inclusion you get more people who meet the diagnosis based on the broadened criteria, which doesn’t translate into an actual increase in cases.

Hello friends –

Regarding the Korea study, the questionaiire in use, the ‘Autism Spectrum Screening Questionnaire’ is designed for detecting high functioning people on the spectrum.

During the last few years, screening instruments have been devised to screen for Asperger syndrome and higher functioning autism. The Autism Spectrum Screening Questionnaire (ASSQ),14 the Australian Scale for Asperger’s Syndrome,15 and the most recent, the Childhood Asperger Syndrome Test (CAST),16 are some of the instruments that are reliable for identification of school-age children with Asperger syndrome or higher functioning autism. These tools concentrate on social and behavioral impairments in children without significant language delay.

If you goto pubmed and search for ASSQ, you get twenty hits.

What they really found was two very different groups, from the autism science foundation blog written by everyone’s favorite monster. [not linking to avoid spam filter]

The prevalence of ASDs was estimated to be 2.64% (95% CI=1.91–3.37), with 1.89% (95% CI=1.43–2.36) in the general-population sample and 0.75% (95% CI=0.58–0.93) in the high-probability group. ASD characteristics differed between the two groups: the male-to female ratios were 2.5:1 and 5.1:1 in the general population sample and high probability group, respectively, and the ratios of autistic disorders to other ASD subtypes were 1:2.6 and 2.6:1, respectively; 12% in the general-population sample had superior IQs, compared with 7% in the high-probability group; and 16% in the general-population sample had intellectual disability, compared with 59% in the high-probability group.

Does it make sense to anyone here that we should place together two groups wherein one group has a 59% level of intellectual disability, and the other group has 16% disability? [Note that prevelance in the ‘high probability’ group is .75%, and in the happy sunshine gifted group, 1.89%.] This is plainly, crazy.

It is well and good to pontificate on the nature of a spectrum, but if a nearly four times difference in the presence of intellectual disability isn’t enough for us to consider that we might need different labels, one wonders what would constitute meaningful differences?

The fix is in to sell the narrative that autism is wildly prevelant and massively underdiagnosed. The narrative that you get from the people who have been in the trenches working with these kids for the past twenty years is exactly the opposite. Bioinformatics will solve this question for us eventually, and the psychiatrists will be left to rot, waving ever more vaque questionairres and insisting on relevance.

– pD

“The narrative that you get from the people who have been in the trenches working with these kids for the past twenty years is exactly the opposite. ”

Hmm, the narrative I got during my brief time ‘in the trenches’ was exactly that autism is more prevalent than recognised and that it is massively overlooked in diagnosis, especially if the person already has a mental health or developmental diagnosis.

Could this be because I’ve only ever worked with adults with autism? I’ve literally seen adults with clear autistic traits go undiagnosed until they were lucky enough to be seen by a consultant with additional training in autism or dual-diagnosis. People who were in Britains old carehome system for decades in some cases.

It is well and good to pontificate on the nature of a spectrum, but if a nearly four times difference in the presence of intellectual disability isn’t enough for us to consider that we might need different labels, one wonders what would constitute meaningful differences?

We already have different labels. That’s precisely why the study provided different statistics for two identifiable subgroups, in fact.

Why do you believe bioinformatics will solve this problem for us “eventually”? Do you believe that ASD is entirely genetic, do you believe that bioinformatics will be able to take into account all environmental factors to determine exactly what the causes were or will be? Do you believe that ASD will be 100% detectable by genetic studies?

Or were you just looking to trash psychologists?

@ Todd W: You provided a more complete analysis of the Korean Study…but there are many more problems with the study, from my viewpoint. For instance, we are unaware of the diagnostic criteria used by educational professionals to provide services to children within the regular school system. Are any of the children on the disability registry in Korea classified with ASD? If they aren’t, that might explain the teasing out of the huge numbers of children that the researchers reclassified as being on the Autism Spectrum, located in the general school population.

The researchers did point to the reluctance of Korean parents to have their children “labeled” with an autism diagnosis due to stigmatizing cultural differences. In western cultures…the United States in particular…having your child diagnosed with ASD opens up tax funded intensive services provided to your child…from birth (Early Intervention Programs) through pre-school and throughout the school years.

Eligibility criteria for these services have changed since the first all-inclusive federal legislation (Education of All Handicapped Children Act) was enacted in 1975. Back then, education law did not have an Autism Spectrum Disorder educational category; the (traditional) Autism category identified kids who were barely verbal or non-verbal or who had echopraxia/echolalia speech patterns and avoided eye contact; many also had self-stimulatory and/or self injurious behaviors as well. Back then, kids were diagnosed with Learning Disabilities, Speech and Language Disorders, Mental Retardation (mild, moderate, severe, profound ranges), Cerebral Palsy, PDD-Other, as well. I served on the COH in my school district as the “Parent Advocate”, back then. Did we “play” with the educational diagnoses? Sure we did, when parents “fought the labels”…we didn’t certify the kids as “Learning Disabled” in order to get the kids some needed services (you could do that then…as long as the kid didn’t get 5 X weekly services). Did we label some kids as “Learning Disabled” when in reality the child had borderline intellect or was mildly Mentally Retarded…you bet we did. It was all part of the process to get the child needed therapies, needed 1:1 services and to get the parents “on board”…back in the day when parents thought another label was stigmatizing.

Different societal acceptance now and different labels (ASD) have an impact on the autism “epidemic”.

Aaron writes:

Name the 1st world nation with the highest number of vaccinations (and recommended vaccinations) before age 2. That same country (U.S.) also has the highest infant mortality rate. Hmm…

Yes, that’s why infant mortality in the USA shot up when vaccinations became routine. Oh, wait….

Angie, are you a sock puppet of Polly? Because you edited that abstract just like Polly, and lilady caught that lie through omission.

Be aware that the time period between 1970 and 1993 includes the 1987 to 1993 measles outbreak where over 150 people died from measles. So how does the 48 encephalopathies and even fewer than ten deaths compare to the hundreds of people with permanent neurological damage, and almost two hundred dead?

Mu,”mental regression and retardation, chronic seizures, motor and sensory deficits, and movement disorders”. This is what autism looks like in today’s children.

A caudal continuation of the spinal cord. This is what legs look like in today’s horses. Therefore a horse has five legs.

Could this be because I’ve only ever worked with adults with autism? I’ve literally seen adults with clear autistic traits go undiagnosed until they were lucky enough to be seen by a consultant with additional training in autism or dual-diagnosis. People who were in Britains old carehome system for decades in some cases.

This is only an anecdote, but my son has been diagnosed with PPD-NOS while my husband does not have a diagnosis–yet my husband’s symptoms are far stronger. I once read a description of Asperger’s that was so like my husband it felt as though they’d interviewed him before writing it. But my husband is functional. Very odd, very quirky, doesn’t have many friends. But he holds a good job, has a high IQ and is a great dad and husband. Had he been born today there’s no question in my mind that he would have a diagnosis, but school systems weren’t handing them out like candy back in the late 60s. And of course my husband wouldn’t be formally diagnosed now unless he sought it out himself. He doesn’t feel a need to do that because like I said, he’s doing well despite being a very odd duck.

Mu,”mental regression and retardation, chronic seizures, motor and sensory deficits, and movement disorders”. This is what autism looks like in today’s children.

Another attempt to paraphrase Polly @ 12:
“A spherical citrus fruit with a colour somewhere between red and yellow. This is what apples look like in today’s fruit. I will now compare the number of apples as I define them with the number of apples as previously defined, and pretend that the result is meaningful.”

Can I just say that while visiting your fine country last week I was blown away by the number of pharamaceutical adverts on TV – especially on CNN when I was watching the Royal Wedding – and later, the Bin Laden coverage. Interspersed at regular intervals were grim appeals for work from lawyers specialised in suing for alleged drug-related damage.

I couldn’t help wondering if this intense climate contributes to the fear and suspicion that leads frightened, disempowered people unable to think rationally for themselves, to find solace and affirmation in the arms of Mercola, Mike Adams, Dr Oz et al. It’s not an excuse for their lunacy – just an observation!

So, when a study like the Korean one comes out, the first question isn’t “are we using a too broad a definition of autism spectrum,” but OMG TEH VAXZINES!!!

Since South Korea has a fewer vaccinations & a lower rate of immunization (posted over in one of the other threads here), I can’t see how this could possibly be seen as any sort of “victory” by the anti-vax crowd.

the masses always follow blindly anyone who rants empty claims, especially when the journalists who have inflated egos about their own incredible powers of persuasion continue to have their most ludicrous mass-hysteria articles published in favour of the truth. The truth isn’t a good seller of news.

@41-among the diagnostic criteria for Asperger’s (as for most psychiatric diagnoses) is-“the disturbance causes clinically significant impairment in social, occupational, or other important areas of functioning.” A highly functional individual may not meet the criteria for the diagnosis. We have to wonder-does giving a highly functional individual a diagnosis of autistic spectrum d/o (or whatever we want to call it) actually do them any good? Or to put it another way (and this has long been an issue in psychiatry) how do we make sure people who need treatment get it without labeling normal variations in human beings pathological?

Orac, knowing that an attack on me by an alleged “30 year student” of radiation, by me on that subject is an obvious and total pack of lies has censored any response to it.

Clearly something only a fascist would do. Lets try again:

Kreb anybody who checks what you say about my link will see that you are lying

#1 of the For Hormesis links is an overview wholly unrelated to what you say
#9 is Professor Cohen on his research which found precisely the beneficial connection between radon and cancer which you assure “undoubtably” cannot be claimed by anybody. It appears doubt is indeed possible, indeed statistucally proven.

I can, of course, understand why you have “learned nothing” that disturbs you prejudices in “30 years” since you clearly never allow facts to interfere with them.

I ask you to acknowledge that my reading of these links is correct and your contention that the latter is a “dating agency” is non-factual.

Comment #47 from Neil seems to belong in this thread from a while ago.

People who haven’t visited the thread, really should. Kreboizen documents how Neil has updated his website with fresh links so he can accuse Kreboizen of lying about the junk it had previously linked to.

This is like playing ‘whack-a-mole’ – this thread keeps popping up all over the place.

I think the junk is still there, just not at the top of the list, where I thought it was previously. As I wrote on the other thread, it’s possible I made a mistake, but it is true that the page has been updated today which makes me suspicious. All the links I referred to were copied and pasted directly from the web page. I am not lying about anything.

I don’t believe I’m prejudiced about this. I think it’s possible that radiation hormesis is a fact, but I also think it’s possible that low level radiation is more dangerous than we currently believe. There are theoretical reasons supporting both hypotheses, and the epidemiological evidence is equivocal, except for radon causing lung cancer which now seems pretty clear. I’m not convinced by the evidence either way.

I certainly don’t see any evidence that convinces me we should abandon all safety standards, as Neil (and Ann Coulter) seems to be suggesting. There is a possibility that exposure to low levels of radiation could be causing large numbers of cancers and deaths, and until we are sure about this, I think we should be cautious.

Cohen’s work is generally accepted to have failed to take account of confounding factors. A review/metastudy published last year looking at over 12,000 lung cancer cases from Europe, the USA, and China found radon is the cause of 9% of all lung cancers, which is in line with the LNT.

I have learned nothing new from your website Neil. I have learned plenty in the 30 years I have taken an interest in this subject, mostly about how unclear the evidence is. I started working with I-125 in the 80s, and had to have my thyroid scanned monthly, on a trolley in a metal box made from a WW1 battleship. All steel smelted since 1945 is contaminated with radioactivity from nuclear bomb detonations, or so I was told by the nuclear medicine people. This piqued my interest about the effects of low level radiation and I keep coming back to the subject.

The dating agency link is still on your web-page – I just checked. It’s about half way down the page and the text for the link is “Extensive evidence suggesting hormesis article”. The link itself is It was presumably once a link to something about hormesis, but is no longer. It’s clearly an old link gone dead and I never suggested it was anything else.

Since I have a couple of links in this comment it will be automatically held up for moderation. No conspiracy involved.

What trash. Couldn’t even read it it was so badly written. Subjective to the point of extreme exaggeration. Work for Pharma?

Well, if it’s like I suggested before, and he’s using a different defintion of “autism” than the rest of the world, it could be to him “autism.”

“What trash. Couldn’t even read it it was so badly written. Subjective to the point of extreme exaggeration. Work for Pharma?”

Orac is not to blame for your lack of reading comprehension. And no, you can’t work for Pharma, your inability to read precludes that. :p

“For the record, the “new atheist” objection to Chris Mooney isn’t that he’s “too critical” so much as that he’s “grossly intellectually dishonest and shamelessly pandering in his criticism of ‘new atheists.'”

I wonder what motivated them to come to that conclusion?

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