Skepticism and the scientific consensus

It figures.

Some of the most interesting questions and posts showed up right before Christmas, just the time when I didn't have time to discuss and (hopefully) expand upon them. Neither, I'm guessing, did anyone else, which is unfortunate because this post was about an issue worth further discussion in the skeptical blogosphere. I'm talking about a post in which fellow ScienceBlogger Martin Rundkvist made this rather provocative observation about skepticism:

A discussion in the comments section of the recent Skeptics' Circle reminded me of something I learned only after years in the skeptical movement.

A real skeptic always sides with scientific consensus.

This may sound really unsatisfying and self-contradictory at first. Isn't skepticism about critical thinking? About being open to any idea (or none) as long as it survives rational deliberation? Doesn't this consensus thing mean that the whole movement is actually just kowtowing to white-coated authority? Well, yes and no.

To begin with, let's remember that there are many people who are strongly skeptical of certain ideas, but who are not counted as part of the skeptical movement. Take Holocaust skeptics, global warming skeptics and evolution skeptics. In the skeptical community, we call them denialists. Why? Because their views go against scientific consensus.

Science presupposes that all participants have a skeptical frame of mind and arrive at conclusions through rational deliberation. If a large group of knowledgeable people working in this way arrive at a consensus opinion, then there is really no good reason for anybody with less knowledge of the subject to question it. Informed consensus is how scientific truth is established. It's always provisional and open to reevaluation, but as long as there's informed consensus, then that's our best knowledge. Humanity's best knowledge.

Although I see where Martin's coming from, I found this viewpoint somewhat disturbing, leading me to echo Martin's own words; Well, yes and no.

For a skeptic, in matters of science it is undoubtedly true that the scientific consensus is always the best place to start an evaluation when evaluating unfamiliar issues. It is certainly possible that the scientific consensus is wrong in almost any area, but the consensus almost always represents the best current understanding of an issue. It is also correct, as Martin argues, that authority matters. Like him, I'm more inclined to accept the pronouncements of someone who has actually dedicated his or her life to studying the issue systematically; i.e., an expert. If the topic is evolution, then that expert would be an evolutionary biologist. If the topic is the Holocaust, then a historian specializing in the Holocaust would represent an appropriate expert. For cancer, an appropriate expert would be an oncologist. The list goes on.

Where I start to have a bit of a problem with Martin's viewpoint is when I start to contemplate the nature of scientific consensus itself in many areas of science. Not all consensuses are created equal because, depending upon the field, the strength of scientific consensus can vary quite markedly depending upon the topic or even the subtopic within the topic. For example, the scientific consensus supporting the theory of evolution, particularly common descent, is exceedingly strong. It's one of the strongest of all scientific consensuses. Similarly, the consensus that natural selection is a major driving force behind evolution is very nearly as strong. However, as the discussion devolves into more detailed areas, inevitably the consensus weakens. Eventually, subsidiary areas of a discipline are reached where the consensus is weak or where there is no consensus, such as what the function of "junk DNA" is, whether it is subject to natural selection, and if so how much. (Real evolutionary biologists could probably come up with a better example.) These sorts of questions are often at the edge of scientific knowledge, and it is not always easy to recognize what they are. It is also these issues at the edge of our knowledge that are attacked as proxies for the much more strongly supported core theory. Creationists are notorious for this sort of tactic.

The same is true of many other disciplines, including my own discipline of medicine and surgery. However, the scientific consensuses are rarely quite as strong as the theory of evolution; usually, the strength of the consensus is proportional to the ratio of data supporting it that comes from randomized clinical trials to data from epidemiological studies, the latter of which are more prone to confounding factors. That does not, however, mean that there isn't a strong consensus about many issues. For example, there is in essence no doubt that HIV causes AIDS, the claims of some notwithstanding. Similarly, there is in essence no doubt that smoking tobacco vastly increases a person's risk of lung cancer and heart disease, along with a host of other medical problems. Not even the tobacco companies try to argue that anymore. When we come to subsidiary questions, though, the consensus is generally not as strong. For example, it has become increasingly appreciated that secondhand tobacco smoke increases the risk of heart disease and lung cancer in people chronically exposed to it. However, because the effect is smaller than it is for people who actually smoke cigarettes, there is a lot more "noise" in the studies, giving a lot of wiggle room to people who dislike the idea of the government banning smoking to claim that such bans are not scientifically supported, and it's taken a long time for scientific and clinical studies to firm up the conclusion enough to the point that it is now a strong consensus.

Not surprisingly, given the difficulty doing controlled experiments and the nature of the material, which makes it more easily politicized or influenced by biases, a truly strong consensus is harder to come by in the humanities and social sciences. However, even so, it is not impossible. For example, one of my areas of interest is the Holocaust. There is overwhelming and incontrovertible evidence that the Nazi regime embarked on a systematic program to round up and exterminate the Jews in territories they controlled. Methods used included shooting, hanging, gas chambers, and a system of camps designed to literally work their inmates to death through a combination of grueling labor, insufficient food, and unsanitary and crowded conditions. However, this consensus becomes less clear when various issues surrounding the Holocaust are discussed. For example, there is the whole "intentionalism" versus "functionalism" debate which, in a nutshell, is the question of whether the intent was there from the very beginning of the Nazi regime or even before (a "master plan," if you will) to exterminate the Jews or whether the Holocaust grew "organically" or "functionally" out of increasing persecution, radicalization of Nazis carrying out the program, and the question of what to do with the millions of Jews that fell under Nazi control after Hitler invaded the Soviet Union. Holocaust deniers love to misuse this debate to claim that Hitler didn't know and didn't order the Holocaust.

The reason this whole question came up relates to a debate that had been brewing for a few months at least but recently bubbled to the surface at the 76th Meeting of the Skeptics' Circle last week over posts submitted by Sandy Szwarc at Junkfood Science. I'll admit that she's a difficult problem and one reason why I've been thinking about these issues lately as I decide how the Skeptics' Circle should go forward and what, if any changes, should be made. Most of her non-obesity-related stuff is often actually not too bad. However, whenever she blogs about diet and obesity, there's usually a problem. And it's not the sort of thing that necessarily jumps right at you off of her blog. Certainly it didn't for me. Rather, it's the sort of thing you have to read her blog closely for a while (which I did) to start to realize. As I read her blog, more and more it bothered me that all of her "skepticism" was inevitably in the direction that being obese is not only not unhealthy but is actually at least as healthy as not being obese, that eating fatty foods is perfectly fine, and that virtually any study she looks at that says that eating fatty foods or too many calories predisposes to health problems is a pile of crap while any pile of crap study claiming otherwise is the latest and greatest. All of this leads her to conclude that virtually every warning made by scientists and physicians about diet is fearmongering. Worse, she has a distressing tendency to use unscientific tactics, such as cherry picking data, attacking consensus, and alleging conspiracies. I also found it telling that, unlike most bloggers, myself included, Szwarc does not permit comments. If there's one thing that skeptics usually encourage, it's spirited debate. That's impossible in a blog that doesn't permit comments.

The end result of this incident leads me to be a bit uncomfortable with Martin's blanket statement that "a real skeptic always sides with scientific consensus." The reason is that what the scientific consensus actually says is not always that clear for many issues, even among those who work in the field. Indeed, there are comparatively few issues in science (evolution, for example) for which a strong consensus exists, and even fewer in the social sciences and history (the Holocaust, for example) for which an equally strong consensus exists. These are very strong consensuses, and to overturn them would require extraordinary evidence, evidence at least equal to the evidence supporting them. Consequently, when someone says that evolution is false or that the Holocaust didn't happen (or the lessor form of Holocaust denial, that nowhere near 6 million Jews died), it's fairly easy to recognize such person as a crank and denialist, and one should not hesitate to label them as such.

But what about consensuses that are strong but not as bullet-proof, usually because, although there is a consensus, there are fairly wide error bars around the predictions or uncertainty regarding the importance of various factors? The prototypical example of this is anthropogenic global warming, for which there is a strong consensus among climate scientists but still a fair amount of uncertainty about the outcome. Another example, of course, is the scientific consensus about the link between obesity and adverse health outcomes. How do we differentiate legitimate skepticism about the consensus from denialism?

This is where I tend to agree with Mark Hoofnagle. It's more about tactics and how evidence is used to support an argument. Scientific skepticism looks at the totality of evidence and evaluates each piece of it for its quality. Cranks are very selective about the data they choose to present, often vastly overselling its quality and vastly exaggerating flaws in current theory, in turn vastly overestimating their own knowledge of a subject and underestimating that of experts. This is perhaps the key characteristic of cranks and the biggest difference between a crank and a true skeptic. In addition, because the mainstream rejects them, there is often a strong sense of being underappreciated, leading them to view their failure to persuade the mainstream of the correctness of their views as being due to conspiracies or money. Antivaccinationists, for example, view the rejection of their belief that mercury in vaccines or even vaccines themselves cause autism by mainstream medicine as evidence that we're all in the pocket of big pharma. Global warming denialists see the consensus as being politically motivated by the desire of "liberals" to tell them how to live. Evolution deniers view evolution as the result of atheistic scientists wanting to deny God. People like Sandy Szwarc view the consensus that obesity leads to health problems as being due more to moralizing and bigotry against the obese, which, whether it is true or not, is an easy claim to make because there has been and is a lot of bigotry against the obese.

What a lot of this distinction boils down to is that crankery, denialism, pseudoskepticism, or whatever you want to call it tends, either intentionally through ideology or unintentionally through an ignorance of the scientific method, to conflate and/or confuse nonscientific, ideological arguments with scientific arguments. This is not to say that scientists and skeptics are free from their own biases, whether ideological or simply a desired result that they hope to find. Far from it. However, skepticism means applying the scientific method to claims, whatever its faults, scientific method is the best method thus far devised to minimize these biases. As scientists, the reason we use the scientific method is not because we consider ourselves superior to the cranks, but rather because we recognize that we are human too and thus just as prone to falling into the same traps as they. Moreover, we know that science is a work in progress and that what is considered correct today may well be modified tomorrow. This change, however, is not brought about by cranks cherry-picking data but by rather skeptical scientists probing for weak spots in our current understanding, making hypotheses, and then testing whether current theory or the new hypotheses make the better prediction. Thus, being skeptical of the consensus is not the mark of the crank. It's how and why that skepticism exists that distinguishes crankery from genuine scientific skepticism. We should not forget that.

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What's bothering you is that consensus in science is sometimes wrong. As a dyed-in-the-wool skeptic, that's annoying as hell because there's the fear that we'll wake up one day and discover that we were wrong, along with all those other guys. But that's part of how science's built-in self-correcting mechanism works. The difference between a skeptic and a crank is that a skeptic tries everything on as a possible candidate for being wrong, whereas a crank cherry-picks ("I'm right, but the entire scientific establishment is wrong.")

So, yes, I agree with Rundkvist - skeptics tend to follow the orthodoxy because given the information that is available at a given time the scientific orthodoxy will tend to be as right as it can be. The one little dollop of magic that makes the whole thing work is the scientists who have the guts to say "I don't know" - as long as we can resist filling the vacuum with B.S. then it'll all correct itself eventually. For we individuals, science can be personal indeed, but if you step back and look at how science is done over the course of generations, you'll see it'll all work out OK.

Very good expansion on a very important subject brought up by Martin. I don't think you really disagree with him at all, though, given that I very much doubt that he's saying we as skeptics must agree with scientific consensus when no such consensus exists. Also I suspect Martin would agree that the support we lend a scientific consensus ought to be proportional to the strength of that consensus. If scientists within a field say "we think it might possibly be this way", skeptics should repeat that, not say "scientists say it's like this, for sure!".

A nitpick, then praise:

"It is also correct, as Martin argues, that authority matters." I understand that here you're using "authority" as a synonym for thorough knowledge and understanding of the relevant subject matter. My nitpick is that this wording may play too easily into the crank's view that the scientists opposing his/her position are merely making arguments "from authority" rather than based on evidence and understanding.

Praise: "What a lot of this distinction boils down to is that crankery, denialism, pseudoskepticism, or whatever you want to call it tends, either intentionally through ideology or unintentionally through an ignorance of the scientific method, to conflate and/or confuse nonscientific, ideological arguments with scientific arguments." (Why is it that I pictured Ann Coulter as I was reading this?)

Exactly. Facts don't care what you believe, or what rhetorical tactics you use.

To be quite fair, scientific attention and consensus can be slow to change if economic incentives are on the side of maintaining the status quo, e.g., the reaction of industry scientists to Rachel Carson's hypotheses regarding the effects of pesticides and herbicides. I suppose it is a matter of degree - at some point there is just too much information from too many sources that hangs together too well to dismiss *all* of it as paid-for conspiratorial propaganda. Cranks, I suppose, don't have inbuilt meters to tell them when they've hit what you might call the "Sagan point." (From the Carl Sagan quote: "They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown.")

Orac, great discussion.

"A real skeptic always sides with scientific consensus."

To be workable, that claim would require there be an online reference manual for "scientific consensus" across all disciplines. Who would publish it? And, is homosexuality a mental disorder (classified as such until DSM-III, 1974)?

Was Einstein a real skeptic? wouldn't Kuhn say something different, perhaps "a real skeptic is he or she who helps build a new scientific consensus". Or "a real skeptic is he or she who has publicly renounced previously held beliefs at least once, based on new evidence".

Evidence-based may be a more objective appellation than "skeptic" or "according to scientific consensus".

Funny enough I've just been having a similar discussion with someone who is a bit of a 9-11 conspiracist, as well as a proponentsist(TM) of the strange view that there was a vast sunken continent called Mukulia at the bottom of the Pacific, which seeded civilisation, which is truly based in Africa. Oh, and he's an "evolution sceptic" also.

His approach was to always ask yourself: "But is it TRUE?"

My view is that this is functionally futile. The correct question is: "But does it WORK?" Does it do what it says on the tin?

I think this is the difference between a real sceptic and a simple denialist/conspiracy theorist. Scientists always want to test their ideas to see if they hold up. Do they explain the data? Conspiracy theorists want to use their preconceptions to select out confirmatory data.

Maybe it's a philosophical thing: denialists are interested in what things *are* (or, rather, what they would like them to be); scientists, scholars, sceptics are interested in what things *do*. It's an important distinction.

By Amenhotep (not verified) on 27 Dec 2007 #permalink

At last! A very reasoned approach to the problem of skepticism and where the tipping point between crankology, denialism and other untenable positions begins. I find, for example, the Hoffnagle position - you oppose consensus therefor you are a crank - to be unreasonably strict. The degrees of strength of the null hypothesis are significant.

If we can agree on the strength of the consensus, then we can discuss a topic from a position of skepticism, minority opinion or pure crankology. If we posit that the value of 1 represents the unformity of consensus - i.e. the earth orbits the Sun and a value of zero to complete disunity of thought - i.e. tomatoes are poison; then we can find out where our own views lie on an issue.

It is important to the discussion that branching elements may offer either more or less certainty in an area of study, be it chemistry, economics, sociology or even religion.

The problem creeps in when there is no agreement on the level of consensus. By your own observation, the scientific consensus can be wrong. In this instance a person may begin their positions as a crank, but through diligent work help evolve the consensus. The Galileo principle. There is a method to determine the statistical likelihood for success.

For example, I am well into the undecided camp on AGW. I am even unsure as to the whole climate cycle. I will admit the possibility that AGW and GW are valid and correct. But I am concerned that in the rush to come to consensus, something significant may have been overlooked. I think this is an important consideration as we are working to develop policy and actions (which are not without cost) on this science. I don't know if I could make an objective statement as to the level of consensus about AGW. It seems to me that the climate (pardon) around this topic has had a chilling effect on any discussion of the level of consensus. See Huffington post on Sen. Feinstein's ban on pthalates in California for an example of policy not supported by science or science that has gone awry.

It's a great topic and one which should have more discussion. I think continuing this dialogue will go a long way towards helping the honestly skeptical separate from the crankoids and denialists (I still don't like that label)!

The scientific consensus among China's health care professionals for quite some time was that there was no HIV or AIDS in China.

A skeptic relies on best evidence, because while the evidence doesn't lie, people do lie about the evidence. These people are not skeptics, regardless of consensus, but dogmatists.

By Robster, FCD (not verified) on 27 Dec 2007 #permalink

This is a discussion I've tried to have with anthropomorphic global warming denialists on a local conservative blog, and I think this is a good summary of it. It's amazing how many times you can point out to a person that, in a complex world where people are highly specialized and educated, it's moronic and arrogant to think that they are in any position to "debate" experts - particularly when their motivation is so transparent - and further, than it's not impressive to be able to find a single example of an expert who doesn't agree with the majority of other experts, because there's 6 billion people on the planet and millions of scientists.

So the question becomes, what makes a "consensus"? I'm a physics graduate student, and I have a qualitative sense of where the center of opinion sits on most issues in physics - but how do you convince a denailist that there is a consensus of climate scientists on board with at least the larger theory of anthropomorphic global warming? A poll? I usually point out the statements of science professional organizations, but apparently they're all part of the IPCC conspiracy... *sigh*

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I really liked where you talked about how the cranks justified themselves especially when it comes to feeling underappreciated and therefore they seem to have a 1-up on the rest of the "biased" scientific community.

Something I'm hoping you might respond to though would be the recent claims of varying intelligence levels among the different races? I'm afraid I don't know a whole lot about it, but it has been brought to my attention as something that if it were true (which I highly doubt) scientists would be rather dubious to come out and say it. I'd love to hear your thoughts

By Mike Spear (not verified) on 27 Dec 2007 #permalink

The problem is in the operative scientific consensus. All known scientists are human, and so have humans needs, wants and foibles, and are capable of self-deception. A scientist may believe they have arrived at a conclusion based on facts and logic, but they could be mistaken. Millions of scientists could do the same.

I think a skeptic is one who doesn't reject data.

There are plenty of things that are believed without sufficient (or actually without any) basis. Many scientists believe such things and have a hard time appreciating that there is no underlying data or logic to support it. For example the concept of "homeostasis".

What exactly in physiology is "static" as "predicted" by homeostasis? Absolutely nothing is "static". I saw a recent paper (I think) in Nature; where the authors invoked homeostasis but then went on to say they were not thinking of a "static" homeostasis, but rather a "dynamic" homeostasis. What exactly is "dynamic" homeostasis? Isn't that an oxymoron? I think it is a "homeostasis of the gaps", that as our knowledge of physiology becomes more complex and we understand that fewer and fewer things are actually "static", that homeostasis will retreat into the regions of physiology where we remain ignorant, the equivalent of the "here be dragons" written on maps of another time.

Where do we separate the emotion and ego from the data and analysis? JeffK details his position on AGW right away through the use of a common invective. By stating that "experts" hold an unassailable position, we should cede to their analysis. I will admit that they provide a stronger position - however, it is not impervious from question, error or improvement.

Espceially in the case of science which drives policy - an open and respectful discussion should and must take place. This means there is room for skepticism and concession on both sides.

daedalus2u:

I think a skeptic is one who doesn't reject data.

But this carries the implication that one has to know all the data before forming an opinion. This isn't feasible, and it is why we have experts. The whole point here is that we trust that the scientists in a certain field know more data than we do and hence we trust them to know better than others when it comes to the field in question. No one has claimed scientists are inhuman or superhuman, just that we have to assume that they represent "the best of our knowledge" - because who else does?

I love this blog, and am finally compelled to comment because this very issue is one I've been obsessing over. I can understand why a scientist like yourself would be leery of the idea that "a real skeptic always sides with scientific concensus", but for a layperson iike myself, it is true and *has* to be true, because laypeople do not have the ability to sort out truth independently. I think that when it comes to medicine or biology or physics, it is ridiculous for me to "think for myself" or "look at both sides with an open mind" because there *aren't* two sides. This comes up over and over on the message boards that I torture myself by reading (about vaccines, etc.) and it's dreadful how regularly people report "well, I've looked at the research, and I'm not convinced either way, so for now I'm not going to vaccinate." (Or "believe" in climate change, or macroevolution, or what have you). I'm a relatively literate person, but I'll freely admit that often, pseudoscientific explanations for phenomena sound true to me, and often the only way I can distinguish between what is true and what is false is to consider the sources. When people have the hubris to think that they can independently sort out their own scientific theories by reviewing evidence from "both sides", the results can be really dangerous, both personally and socially. Because, of course, there aren't "two sides" to any question. There are countless "sides" and when an overwhelming concensus has been reached, then yes, I'd be a fool to decide I'm going to take a minority position.

I love this blog, and am finally compelled to comment because this very issue is one I've been obsessing over. I can understand why a scientist like yourself would be leery of the idea that "a real skeptic always sides with scientific concensus", but for a layperson iike myself, it is true and *has* to be true, because laypeople do not have the ability to sort out truth independently. I think that when it comes to medicine or biology or physics, it is ridiculous for me to "think for myself" or "look at both sides with an open mind" because there *aren't* two sides. This comes up over and over on the message boards that I torture myself by reading (about vaccines, etc.) and it's dreadful how regularly people report "well, I've looked at the research, and I'm not convinced either way, so for now I'm not going to vaccinate." (Or "believe" in climate change, or macroevolution, or what have you). I'm a relatively literate person, but I'll freely admit that often, pseudoscientific explanations for phenomena sound true to me, and often the only way I can distinguish between what is true and what is false is to consider the sources. When people have the hubris to think that they can independently sort out their own scientific theories by reviewing evidence from "both sides", the results can be really dangerous, both personally and socially. Because, of course, there aren't "two sides" to any question. There are countless "sides" and when an overwhelming concensus has been reached, then yes, I'd be a fool to decide I'm going to take a minority position.

Once one grants Martin Rundkvist the reasonable interpolation that the strength of one's respect for any given scientific consensus should be proportional to the strength of the consensus itself (that is, the breadth of consensus among experts and the depth of the evidence on which the consensus is based), Orac & Martin seem to be in essential agreement - as suggested by Felicia Gilljam in the second comment.

But Orac also discusses the methods and characteristic attitudes of the denialist/crank/faux skeptic. I would note, though, that the methods of the crank are quite secondary: After all, if there really is a broad consensus based on lots of evidence, then the only possible way for someone who would deny the consensus to make any argument is to make some sort of bogus/fallacious argument - hence cherry-picking, poisoning the well (the appropriate generic fallacy label for all claims of conspiracy), etc. All the legitimate, well-reasoned, evidence-driven arguments lead to one conclusion: That's why there's a consensus in the first place. So naturally the only way to "argue" against that consensus conclusion is to generate illegitimate pseudo-arguments. There are, in the arena of debate at least, no other tactics available to cranks.

So really, then, Orac's addition comes down to pointing out the characteristic attitude of cranks, demonstrated in their habit of "vastly overestimating their own knowledge of a subject and underestimating that of experts," and the closely related tendency to presume conspiracy amongst those who disagree with them. But what do those attitudes and behaviors spring from? It seems to me that EVERYTHING about crankery - the egotistical psychology, the persecution complex (and the accompanying assumption that those who disagree are "in on" or dupes of some conspiracy), the flawed reasoning and fallacious argumentation - has a single common cause: The absolute conviction that some belief of theirs is TRUE and RIGHT (there are always moral overtones in such strong convictions) without justifications that correspond to the strength of the conviction, and often without any justification whatsoever.

In other words, crankery is just another faith-based initiative. Once a conclusion is determined in advance by faith - and of course, a conclusion determined in advance is not really a conclusion at all, but an assumption - any "argument" that follows is necessarily mere rationalization rather than genuine evidence-driven reasoning. A true believer is a true believer, with or without the trappings of religiosity. And, of course, religious dogmatism and anti-science crankery/denialism can overlap - hence creationism in all its forms. Come to think of it, the only difference between the garden variety anti-science crank and a typical religious fundamentalist is that the latter relies upon the external authority of a holy text or religious leader/institution, whereas the former is ultimately his or her own deity (but just as authoritative in his or her own mind).

In this framework, the entire Intelligent Design political movement can best be described as stripping the overt reliance on external religious authority from creationism - motivated by U.S. Supreme Court decisions - and replacing it with the "It looks too complicated to have evolved to me!" internal authority of the cdesign proponentsists. From the standpoint of actual evidence-driven reasoning, this is a difference that makes no difference, hence the essentially indistinguishable character and methods of cdesign proponentsists and earlier Bible-citing creationists. Both start from an identical assumption, Goddidit!, and construct rationalizations (rather than arguments) to support their "conclusion."

Good post! I can't find any disagreement between our positions.

Wrote I, "On many issues, of course, there is no scientific consensus. Here, skeptics have every reason to exercise critical thinking and arrive at an opinion of their own. Or to reserve judgement."

I was pleased to see the reference to the scientific consensus on homosexuality in DSM III. As a non-scientist my only recourse in such a situation would be to voice my moral objections to its inclusion. If I were an historian I could mount a critique based on changing concepts of normalcy and deviance across time. An anthropologist could point to cross cultural parallels in the world today. A gay rights activist might choose to "out" some prominent gays, preferably leading members of the psychiatric profession.

Should we have had to wait for scientific studies to undermine the consensus? Could our efforts actually have opened up a space for ethologists to produce relevant animal studies and for psychiatrists to acknowledge the social biases in current psycho-sexual theory and propose a more inclusive consensus for the future?

How should we distinguish between valid non-scientific challenges to scientific orthodoxy and those based on crankery? Is there a reliable test?

It can be extremely difficult to distinguish between crankery and paradigm shifting challenges to scientific orthodoxy. There are a large number of scientific peers than cannot reliably tell the difference. That is what Thomas Kuhn argues in his book on the structure of scientific revolutions. Scientists only work within a scientific paradigm, with unacknowledged assumptions about reality (and hence assumptions that can't really be tested by the scientific method within that paradigm). Hypotheses that challenge those assumptions are not analyzable within that paradigm. Relativity is not analyzable within the assumptions of absolute time and space within Newtonian physics.

Millikan couldn't accept that Einstein's photoelectric effect was valid, even when it was Millikan's own data that proved it to virtually everyone else.

http://en.wikipedia.org/wiki/Robert_Millikan

The bottom line has to be data. Any and every hypothesis or model has to fall if it doesn't fit the data.

If scientific peers in their field of expertise can't tell, how can a non-expert? They really can't, and shouldn't try to. The hallmark of an expert is to know the limits of their expertise. Most cranks have not a clue as to the limits of their expertise, and human nature being what it is, it is very difficult for scientists (or anyone) to acknowledge they don't know something. Particularly when a crank is ready to step right up and say they do know. A case of "fools rush in where angels fear to tread".

However, true scientific disputes are very rare. In a true scientific dispute the vast body of data would be accepted by both sides, there would just be two different interpretations. In such a circumstance we would prefer the one that fits the data better and makes more accurate predictions. In the marketplace of ideas that doesn't always happen very quickly. If Millikan had been the editor of the journals Einstein published the photoelectric effect in, would he have allowed it to be published with limited confirming data? Millikan wasn't a crank, he was intellectually honest enough to publish his data which confirmed the photoelectric effect which he did not believe was correct. Cranks don't have that kind of intellectual honesty.

A problem with "consensus" is the ease with which the term can be abused. A quote mine here, a statistical flub there, and a crank in between lets anti-science types hide behind a claim that there is no consensus or that a certain concept within science is about to collapse.

By Robster, FCD (not verified) on 27 Dec 2007 #permalink

I can understand why a scientist like yourself would be leery of the idea that "a real skeptic always sides with scientific concensus", but for a layperson iike myself, it is true and *has* to be true, because laypeople do not have the ability to sort out truth independently.

This hits the important point, I think.

Martin Rundkvist makes something close to an excellent point. But it would have to be changed a little bit before I could agree with it. I think a better way to word what Marvin meant might be that a real skeptic always considers the scientific consensus to be the default position.

Put in other words: It is not enough to call yourself a skeptic just because you are skeptical of others. You must also be skeptical of yourself. Part of being skeptical of yourself means not automatically assuming you know more than other people. Sometimes there's good reason to believe you know more on some subject than certain other people do-- say, you have made an extensive study of the subject. But sometimes there's good reason to believe other people know more on a subject than you do-- say, they've made extensive study of the subject and you haven't. When that second case arises, you should give the other person's greater knowledge appropriate weight. You can still challenge that person's opinions on the subject in a skeptical way! You can ask them to defend or explain their opinion in a way that reveals what in their grounding of knowledge caused them to form that opinion. You can study the subject yourself so that you have the grounding to challenge their opinion as a relative equal. But you have to realize there's an entry cost there-- with both of these options, you're effectively only able to skeptically challenge the expert's opinion by attempting to rise to that expert's level of knowledge.

What you can't do when confronted with such an opinion, on the other hand, is say things like this: "Well, I don't really know much about the subject, so I'm just not going to conclude either way". This is not a skeptical statement; in fact it's downright megalomaniacal. Someone who would say this is effectively saying, I don't have expertise on this subject, therefore neither does anyone else. It could be reasonable, and skeptical, to make a slightly different statement closer to "I'd like to learn more about the subject myself before I draw conclusions". But again, this is subject to the entry cost mentioned above, the entry cost of actually acquiring some knowledge of the subject yourself.

A skeptic can, and should, demand that they get to see the evidence for any claim. But if someone doesn't have the time or desire to look at that evidence, then skepticism followed to its logical ends would imply that the default conclusion should lie with the consensus, if one exists, of credible experts on the subject. Someone who does otherwise is after all claiming that their ignorance should be given more weight than an expert's knowledge, and that's practically the opposite of what skepticism means.

Coin's modification of the statement is precisely what I would do. I was going to comment to that effect as well before I read his comment. ^_^

With that slight modification, I think I can accept the statement whole-heartedly. It states that the consensus is valuable (as it most certainly is) without tying one to a dogmatic acceptance of consensus. A good scientist can go against consensus if they have a very good reason to believe the consensus is wrong, and subsequent work supports them. However, us average joes should and must accept the consensus as the most accurate position by default.

By Xanthir, FCD (not verified) on 27 Dec 2007 #permalink

The only reason that science works is that scientists look at the evidence, not the beliefs of other scientists, to determine their own beliefs.

If you pay attention to other people's beliefs, it becomes trivially easy to start a feedback of belief that isn't actually founded on anything.

If you're not competent to examine the data, verify the logic, or test the conclusions, you're not competent to have a position on the topic.

The only authority in science is the world itself. Consensus is a byproduct of the process of examining the evidence and testing hypotheses - it cannot be substituted for that process.

By Caledonian (not verified) on 27 Dec 2007 #permalink

Maura wrote:

When people have the hubris to think that they can independently sort out their own scientific theories by reviewing evidence from "both sides", the results can be really dangerous, both personally and socially.

Excellent point and comment. I also see this over and over when I try dealing with anti-science enthusiasts -- and am amazed at how the skeptical position has shifted in their minds to "arrogance," and demanding equal respect for the self-made opinion is "humility."

Some of this seems to be based on the idea that it's wrong to hurt feelings, or deny someone's "personal experience" or own search for truth. And to add to G Felis' "faith-based initiative" idea, I also get a sense that there's an underlying belief that the universe must be understandable to the average person, since it's all about nurturing and fostering simple spiritual truths. Be sincere and spirit will guide you -- a sort of "mommy instinct" everyone can borrow. Nothing is meeker than following your heart.

It's interesting how often religion will come up on topics which seem to have no direct connection. You're talking about homeopathy or psychic abilities, say, and they'll suddenly ask "do you believe in God?" The idea seems to be that if you say yes, then you know there are truths that can't be proven, so point to them. And if you say no, then you're not the kind of person who is open to those truths that can't be proven, and there's nothing more to be said. Another point for them.

Sastra, if you hadn't already been awarded a Molly - and if this weren't another blog entirely - I'd nominate you. :-)

Yes, I cannot help but see a fundamental connection between a broader "religious impulse," the tendency to embrace woo, and crankery. It's all down to taking some claims about the world on faith, in the absence of evidence (and sometimes in the presence of counter-evidence). Once you swallow that pill, just about anything follows...

Although I forgot to link to it before - and how rare for me to miss an opportunity to toot my own horn! - I recently wrote about the fundamental arrogance of those who take their own ignorance more seriously than the hard-won conclusions of actual experts who have spent their lives in study and research. Which is to say: You rock, Maura! I wish you hadn't posted your comment while I was writing mine. I would have gladly expanded on your wise words as the basis for my own contribution.

Interesting discussion all 'round. Thanks, Orac, for bringing it up!

Caledonian wrote: If you're not competent to examine the data, verify the logic, or test the conclusions, you're not competent to have a position on the topic.

The only authority in science is the world itself. Consensus is a byproduct of the process of examining the evidence and testing hypotheses - it cannot be substituted for that process.

True, but even Newton referred to "standing on the shoulders of giants," and virtually all scientific papers in the peer-reviewed literature cite other papers. I assume no scientist has time to verify all supporting evidence for his/her conclusions from primary observations. So inevitably it becomes a question of whose conclusions you trust - on whose shoulders do you choose to stand, and with regard to what topics?

That's referencing data, not using a consensus as data.

One of the reasons why experiments have to be replicated so often, and scientists have to share the details of the experiments they did, is so that it can be verified that one person neither screwed up the experiment nor lied about their results.

Not only do we not trust the opinion of the group, we don't trust the opinion of individuals. The data trumps everything.

The data trumps everything.

By Caledonian (not verified) on 28 Dec 2007 #permalink

Caledonian wrote:

If you're not competent to examine the data, verify the logic, or test the conclusions, you're not competent to have a position on the topic.

Whilst I can see what you're getting at Caledonian, I have to disagree. We are often obliged to take positions on subjects for which we simply do not have the resources to thoroughly research ourselves.

Take global warming - we all (well, those of us that live in democracies) are starting to have to take a position on this, as candidates are pushing opposing views. What are we all supposed to do? Throw our hands up in disgust and abstain? Become climatologists each and every one of us? Clearly, we MUST take a position. Equally clearly, as has been stated by others here, that position, for a skeptic, must be aligned with the consensus view. Only in the case where a consensus does not exist should we even attempt to apply our own understanding of first principles.

But regardless, there is no escaping the need to take a position, even when we aren't necessarily personally competent to do so.

By demallien (not verified) on 28 Dec 2007 #permalink

she has a distressing tendency to use unscientific tactics, such as cherry picking data, attacking consensus, and alleging conspiracies. I also found it telling that, unlike most bloggers, myself included, Szwarc does not permit comments.

Is there no possibility at all that the critics of Sandy Szwarc have cherry-picked the more questionable of her posts and frequently alleged conspiracies about putative agenda, allegiances etc.? Mark H's success in persuading Medgadget to de-list her from the Med Blogging Awards (Dec 19, 05:05 and Dec 20, 12:38 PM) might persuade the onlooker that there is some concerted action to block even the consideration of her ideas.

After careful review, we have withdrawn Junk Food Science blog from the competition. For those of us that deal every clinical day with the devastating effects of obesity, diabetes, HTN, etc, ideas presented in that blog are beyond recourse. The site does not present a scientific debate that can be reasoned with.

Quite a number of the nominated blogs recount experiences and viewpoints, it seems extraordinary that only Sandy Szwarc is singled out for lacking 'scientific debate'.

As for the commenting issue, it is unfortunate. However, I know that several bloggers have actually given up blogging sooner than run the risk of various threats of legal action relating to comments and what various commenters said about each other (NeoNatal Doc comes to mind as someone who has had a skirmish with this). Given the heightened rhetoric around this issues, is there any way in which such a controversial blog would be anything other than a bear-pit in which people hurled epithets rather than exchanged views and ideas?

I'm disappointed that Medgadget did not have the courtesy to post the findings of their "careful review". Labelling someone a denialist on the basis of a couple of take-down posts but mostly snarking and unsubstantiated assumptions about her agenda seems wrong: it's a serious charge and one would have thought that the case and evidence would need to be commensurately serious and documented.

Publications in epidemiology appear to be disproportionately criticised as a morass of poor statistical techniques; this is more likely to be an example of difficult controls and very real-world problems than any notion that epidemiologists can neither conduct good studies nor analyse their results correctly when examining anything more subtle than smoking and ill-health.

Recently, there was some controversy in the UK when some specialists roundly condemned the statistical analysis that underpinned predictions for the future costs of obesity to the UK. Prof Spiegelhalter was one of the critics and a senior figure in the public understanding of science. He rather seemed to share some of Szwarc's concerns about the careless assumptions and analyses that underpin some epidemiological data in this field.

Beyond that, Speigelhalter has achieved the remarkable feat of being quoted on obesity matters in a british tabloid:

Prof Spiegelhalter discovered that patients who had weight-loss surgery were more likely to kill themselves than those who had not shed the pounds.
In the New Year a team of experts at Heriot-Watt University will unveil research which shows it is more dangerous to be skinny than tubby.

They found, on average, fatties will live around ten years longer than skinny minnies.

It is understood that there are persuasive and plausible physiological mechanisms that support the widely-held belief that obesity is intrisically damaging to us. However, by the time that these findings make their way into the mainstream media they are devoid of all value. The same media that publicise photographs of a 90 lb woman and caption her a fat pig are none too helpful at assisting people to calibrate the differences between normal weight, overweight, obesity and morbid obesity and the health sequelae.

I use these examples because media appear to relish epidemiological studies and their headlines as more attractive than fascinating indications that e.g., bodyfat may form another endocrine system or that it promotes/reduces some bio-markers of inflammation. As for the epidemiological data that Szwarc criticises, it seems as if the much-admired Spiegelhalter may have occasion to make similar arguments.

Maybe there isn't as clear-cut a consensus in some areas as there seems to be. Until such time as the public dissemination of research findings is sufficiently nuanced to encompass what is meant by overweight/obesity; co-morbidities and enhanced medical monitoring etc., maybe there is a need for a blog to point out the mis-representation of epidemiological data and to temper the absurd optimism with which some findings are trumpeted about.

Equally clearly, as has been stated by others here, that position, for a skeptic, must be aligned with the consensus view.

No. A skeptic must reject the consensus view if it contradicts the available evidence.

By Caledonian (not verified) on 28 Dec 2007 #permalink

How does a skeptic know that a consensus view contradicts the available evidence if he is not an expert in the field?

A pretty tough task, if you ask me.

I view this new assertion with interest in light of your previous assertion: "If you're not competent to examine the data, verify the logic, or test the conclusions, you're not competent to have a position on the topic."

It would seem to follow from your reasoning, then, that only experts can question a scientific consensus.

By the way, I'm with demallien on one point. For many issues, it's impossible for nonexperts not to have to have an opinion on a scientific consensus, something you say that nonexperts shouldn't express. After all, politicians right now are trying to decide what to do about global warming, for example. None of them that I'm aware of are climate scientists; yet before they can decide on a policy they have to decide whether they accept or reject the scientific consensus on global warming and how strongly. Voters, whether you like it or not, must also do so. So must skeptics who want to vote or influence policy. A myriad of other scientific issues that impact politics and law come to mind.

Of course, accepting the consensus and deciding what policy measures to take based on it are two different things, but, like it or not, nonexperts are the ones who are going to have to sort these things out.

Orac well written article. But could it be that scientists can be cranks to? I started reading your blog when someone on Michael Siegel's blog linked upto this article on MarkH's blog and followed the link to your blog. I have been a fan of both blogs ever sense but mostly hang and comment on Michael Siegel's blog. I discovered his blog while searching for articles on the (un)intelligent design movement. But I disagree with your statement in the current article that:

For example, it has become increasingly appreciated that secondhand tobacco smoke increases the risk of heart disease and lung cancer in people chronically exposed to it. However, because the effect is smaller than it is for people who actually smoke cigarettes, there is a lot more "noise" in the studies, giving a lot of wiggle room to people who dislike the idea of the government banning smoking to claim that such bans are not scientifically supported, and it's taken a long time for scientific and clinical studies to firm up the conclusion enough to the point that it is now a strong consensus.

Yes I am well aware that the Surgeon General in his press release stated that "In the course of the past 20 years, the scientific community has reached consensus on this point." And further that:

â¢Secondhand smoke exposure causes heart disease and lung cancer in adults and sudden infant death syndrome and respiratory problems in children.
â¢There is NO risk-free level of secondhand smoke exposure, with even brief exposure adversely affecting the cardiovascular and respiratory system.
â¢Only smoke-free environments effectively protect nonsmokers from secondhand smoke exposure in indoor spaces.
â¢Finally, the Report concludes that, while great strides have been made in recent years in reducing nonsmoking Americans� secondhand smoke exposure, millions of Americans continue to be exposed to secondhand smoke in their homes and workplaces.

As Dr Siegel has already pointed out the Surgeon General's statements are not supported by the report itself. What may interest you is a new book due out by ChristopherSnowdon entitled Velvet Glove Iron Fist: A History of Anti-smoking. Though the book is not out yet, the author has made several chapters available on the web. Of most interest to you would be Chapter 3 called 'Your body belongs to the Fuhrer' which discusses Hitler's anti-smoking campaign. Of most interest to me is that he researched all the journal articles believing the consensus opinion true that second hand smoke (SHS) is harmful and walked away believing the the research only support the null hypothesis. As a courtesy to Dr. Siegel's readers he summarized all topics in all chapters what he found regarding SHS in a special article and includes a second article providing his evidence. You may also find that interesting. But his conclusion goes against the consensus. Currently he makes six chapters available they are 1, 2, 3, 10, 11, and 13. As a history buff they all might make good reading for you.

Caledonian is exactly right, if the consensus doesn't fit the data, the consensus must be rejected.

The major problem with epidemiology studies is that they only measure associations. In the case of obesity, the subjects all have chosen how much to eat. BMI may not be an independent variable. It may completely depend on something else that is not measured.

I suspect the underlying problem is low NO, which reduces mitochondria biogenesis, forcing more ATP to be generated from glycolysis. If ~5% of ATP demand is shifted from oxidative phosphorylation to glycolysis, glucose demand by that cell is doubled. The vasculature can't deliver 2x glucose to each cell without increasing glucose concentration. Glucose import is active and saturates. Insulin increases GLUT transporters, but that saturates too. Cells far from a capillary only get the glucose and insulin that isn't consumed by the intervening cells. The concentrations that "matter" are the concentrations adjacent to each cell in the extravascular space, not the concentrations in bulk blood (which is the only place it can be measured). Glucose and insulin levels have to be lower in the extravascular space because that is where they are consumed.

As mitochondria number drops and ATP demand from glycolysis goes up, what is the next limit that is reached? Can the liver continue to generate enough glucose? It can only generate glucose from lactate if it has enough mitochondria. If it doesn't have enough mitochondria, the lactate has to be gotten rid of somehow, perhaps by being turned into lipid. In the liver, in adipose tissue, and eventually everywhere there is spare mitochondria capacity (ectopic fat). The liver can still make glucose from alanine even without ATP from mitochondria, but that takes alanine which can only come from protein reserves, from skeletal muscle as in cachexia.

If the cells "too far" from a capillary still don't have enough glucose to make enough ATP, they send out "I am starving" signals to increase the delivery of glucose and insulin to them. Hyperglycemia, insulin resistance, and hypertension (to increase extravascular volumetric flow) are logical compensatory responses that are adaptive in the short term, but maladaptive when carried out for too long.

If the problem is insufficient NO for mitochondria biogenesis, blocking compensatory hypertension isn't going to fix it.

The association of obesity with carbohydrate consumption may come from the need to supply glucose and insufficient liver capacity for gluconeogenesis. Disallowing consumption of sufficient calories to maintain glucose supply to the brain is going to cause chronic low ATP in the brain, which is often (usually) associated with depression and suicide.

I appreciate that some of these ideas go against "conventional" wisdom, but I think they are a better explanation of the data, of all the data, not cherry-picked data. A NO-mitochondria hypothesis also fits the metabolic data, why obesity is associated with low endurance and an increased basal metabolic rate. That comes from fewer mitochondria generating the same ATP at a higher potential where there is more slip and reduced efficiency.

Dan,

This is my take on Siegel. Since then, I've become even a little more uncomfortable with him; he seems to relish his "maverick" role just a bit too much. (Sometimes I wonder if there's a bit of a personal vendetta in there, given how vociferously he attacks certain anti-smoking activists.) Indeed, given how often he criticizes studies about the adverse health effects of secondhand smoke and that I can't recall ever seeing him praise such a study on his blog, I would really, really like to ask him why he still says he thinks secondhand smoke is a health risk, given that what he posts on his blog is unrelentingly negative about the studies supporting the link between SHS and heart disease, lung cancer, SIDS, etc. He also uses crank-like language (Fumento- and Milloy-speak like "junk science," which makes me uncomfortable.

In other words, although I don't think Siegel is a crank now, his posts on his blog sometimes make me worry that we may be witnessing his evolution into a crank.

Jud, if you don't have time to understand the data that conclusions are based on, you don't have time to really understand the conclusions.

Sometimes that is ok, the conclusions of others might be correct. But they might not be. You can't be a "skeptic" if you don't understand the path from data to conclusions. The alternative to being a skeptic is not to be a raving idiot. One can know the limits of one's knowledge and expertise and be a skeptic within those areas, and tentatively accept the scientific consensus outside your own expertise.

demallien, one is always competent to take a position, even if that position is "I don't know".

In the case of global warming and choice of politicians to deal with that issue, if one is not competent to understand the data and understand the science behind global warming, and also understand the science behind the mitigation policies that must be implemented and how to implement them, one can understand the process by which a politician reaches a conclusion. Knowledge of global warming is quite useless in evaluating the competence of a politician, except by the politician showing him/herself to be incompetent in that area. What is important is the process by which a politician chooses advisors and the people to actually decide what needs to be done and to actually do it.

Do they listen to the advice of scientists who have studied the problem, or do they listen to non-scientific political advisors? Do they seek solutions based on the latest understanding, or do they try to find solutions in a book written 3,000 years ago? Or 150 years ago? Or in the latest peer reviewed journals? Are the solutions they seek robust? flexible? not based on wishful thinking? can they change in the face of new data?

As Caledonian says, the data trumps everything. If you can't take your understanding back to data, you don't really understand it.

I find it more than a little interesting that philosophers and medical doctors, who are more likely than not informed about global warming matters by the popular press, have less understanding of these science issues than those working in mechanical engineering, computer sciences or a very well read layperson. It seems presumptious to tell an audience that consensus is the avenue for the skeptic. I'm no "denialist" (god knows the "D" word is fraught with baggage, and the use of it to lump Holocaust deniers and "skeptics" of man caused global warming is in my opinion irresponsible, hyperbolic and poor broad brush argumentation) and I'm no fan of any kind of woo. I am however willing to look at the motivation and qualifications of those who present information and argument about such ideas as global warming and weight and nutrition issues. Much research being done at universities is clearly influenced by the business, political and social philosophies of those paying for the research. Lay people know that scientists are as human as they are and are as susceptible to avarice, greed, pride and arrogance as the next person. Given the scientific consensus that existed in the areas of eugenics and race a few short generations ago, and the social science and economic experiments that brought us the tens of millions killed by communism, the ascendant should be careful about making specious proclamations about consensus. Consensus is a good thing in many respects but the average reasonable person knows that the achievements of science have nearly always been two edged swords that can and often have been used to harm those with less power, less education and less money. Bombs and bullits aside Rachel Carson is a classis example of the ongoing hubris of the "scientific" environmentalists that seem more than happy to relegate millions to a hideous death or blindness just to hold fast to a "consensus", and frankly wrong, notion that DDT use will destroy the environment. The world bank is increasingly less inclined to provide finding for power plants in third world countries, which will only improve the lives of people in those countries, to satisfy the "consensus opinion" of those opposed to polluting power plants. You would be surprised how many poor illiterate rural Africans know that electricity is essential to provide adequate refrigeration for vaccines and antibiotics.

I've been in the mental health and social work field for twenty five years; specifically investigating child abuse for the past twenty years. It has always amazed me how often doctors and school teachers have proved to be some of the most biased, opinioned and obtuse professionals I've dealt with regarding matters of child abuse. Their opinions are presented to me with great authority and demands for action on my part. It's an easy dynamic to understand because child abuse is a very emotional and often disturbing issue for a doctor or teacher to deal with. However as with many concerns that elicit emotional responses the best intentioned individual only holds more tightly to a view, theory or opinion because of the weight of emotion that's attached. Hearing an opposing view, let alone changing your mind, based on evidence is difficult for most people. Many of the scientists that are purported experts on issues are paraded out and quoted in the media. Only later one often finds that their field of expertise is not what they have been spouting on about and they in fact belong to a highly agended political organization that's not involved in any real scientific research . Doctors prescribe medicines all the time based on the antidotal evidence of their own experiences. So the average Joe should not be a responsible educated consumer of medical services??? Based on the logic that the ascended and knowledgeable should be trusted with the real scientific opinions and decisions, the reasonable course for a skeptic should be to simply accept the judgment of his doctor in any and all decisions medical, because they have not attended medical school... . What hubris and arrogance. It's no different with regard to issues like global warming. The lay person can make informed decisions and call experts to account for what appears to be shoddy or poorly executed research. Lay persons can point out that there are other experts who disagree and make the reasonable and reasonably skeptical decision to disagree with the experts. Some theories are difficult to prove and the supporting evidence is based on postulation and extrapolation. Computer modeling is a very sophisticated form of postulation and extrapolation. I'm much more likely to trust the results of a series of double blind clinical studies of a medication than a climate theory based on prognostic modeling that has inherent uncertainties that can not be reasonably explained away or effectively eliminated from the process. If we plan a course of medication for a disease then we better know for sure that the medication will not kill the patient sooner than the disease. If we only have consensus and not a reasonable level of certainty then perhaps it's better to keep the medicine in the bottle and get more information before we write prescriptions with immense and unforeseen consequences.

By James Fox (not verified) on 28 Dec 2007 #permalink

Hats off to Orac for an enormously valuable post that I predict will become an Internet classic.

By Steve LaBonne (not verified) on 28 Dec 2007 #permalink

This is my take on Siegel. Since then, I've become even a little more uncomfortable with him; he seems to relish his "maverick" role just a bit too much. (Sometimes I wonder if there's a bit of a personal vendetta in there, given how vociferously he attacks certain anti-smoking activists.) Indeed, given how often he criticizes studies about the adverse health effects of secondhand smoke and that I can't recall ever seeing him praise such a study on his blog, I would really, really like to ask him why he still says he thinks secondhand smoke is a health risk, given that what he posts on his blog is unrelentingly negative about the studies supporting the link between SHS and heart disease, lung cancer, SIDS, etc.

Orac, see the same thread and read my comments on it especially the last two posts. I intended to get back to it but more pressing issues prevented it. I agree that there may be that vendetta thing going on as he was a former student of Dr. Stanton Glantz the King of Tobacco Control (TC) and Mr. Crank Scientist himself who put out the claim that even 30 minutes of exposure can cause heart attacks in even healthy persons. But go through a few postings on Dr. Glantz's Listserver starting here and you will see what I mean. As to why he thinks SHS is a health risk, he was responsible for many of the studies that show SHS is a risk and saying that it is not is to admit he was wrong. He takes issue with TC making more and more grandiose claims not supported by science in order to pass more and more smoking restrictions including outdoors and in the home. Claims in the last year include smoking causes impotence, smokers are child abusers, smoking causes loss of eye sight, smoking causes breast cancer (or at times is responsible for all cancers), smokers are less intelligent, etc and these all may apply to those exposed to SHS as well. He believes the evidence based on the science alone is strong enough for indoor smoking bans that TC does not need to make claims not supported by science to achieve their agenda. TC, however, believes the science does not matter as long as the end justifies the means. I believe not speaking out against the claims not supported by sound science will give all of public health a ban name and no one will believe any of it anymore.

Bombs and bullits aside Rachel Carson is a classis example of the ongoing hubris of the "scientific" environmentalists that seem more than happy to relegate millions to a hideous death or blindness just to hold fast to a "consensus", and frankly wrong, notion that DDT use will destroy the environment.

Parasitic insects have already evolved resistance or even immunity to DDT in the places in which it was used. I can conceive of an insecticide known to have DDT's links with cancer, bioaccumulation issues, and known ecological toxicity, but that is sufficiently effective to justify its use in certain value systems. I cannot conceive of using such a pesticide despite its not working.

By Caledonian (not verified) on 28 Dec 2007 #permalink

The fascination with the supposed injustice done to DDT is one of the more obscure and bizarre corners of antiscience wingnuttery.

By Steve LaBonne (not verified) on 28 Dec 2007 #permalink

daedalus2u wrote: Jud, if you don't have time to understand the data that conclusions are based on, you don't have time to really understand the conclusions.

I was speaking of the time it takes to either derive the data oneself or to verify its derivation step-by-step, not the time taken to *understand* data that may well have been derived by others. I don't have to go into orbit personally with a cesium clock and compare it to a cesium clock on the ground once I get back to (1) trust that such data derived by others is as represented; (2) understand what the data is telling me; and (3) understand the conclusion, i.e., the principle of relativistic time dilation.

I don't disagree that the data trumps everything. I'm saying that trusting no one else to derive the data that you work with and are able to draw conclusions from is far too paranoid, and flat-out impractical. Do you really think Orac has time to do all his own blood work, radiology, etc.? Why should modern science forego the efficiencies that division of labor brings?

Does the cherry picking of facts always result in an unjustified skeptic? Computer modeling of proven physics, such as fluid dynamics, is a useful tool. Computer modeling of unknown physics is only useful when the model is accurate and predictive. The current AGW computer models have not been accurate in their temperature predictions. This is not to say that the AGW is wrong, simply that a skeptic would be justified in pointing to the models as a reason for doubt.

The current AGW computer models have not been accurate in their temperature predictions.

If I recall correctly, the models have been far too conservative in their predictions, such that we have already surpassed the worst-case scenarios of ten years ago.

That doesn't seem like justification for doubt of AGW... doubt of the models, yes.

By Caledonian (not verified) on 28 Dec 2007 #permalink

Self assurance is the antithesis of skepticism, and yet this post (not to mention that of Rundkvist) and many of the comments appear to be suffused with self assurance. Clearly, we are skeptics, others are deniers - AGW deniers, holocaust deniers, evolution deniers. We may still have to discuss the fine points of the distinction between skeptics and deniers, but even without a definition, the classification is known.

Note, for example, how, since "we" are all good "dyed-in-the-wool skeptics", we can easily reconcile the authority-based approach of Rundkvist with the method-based parts of Orac's approach. The first focuses on the scientific establishment, the latter focuses on the scientific method - but could any non-crank doubt that the scientific establishment is the epitome of the scientific method?

I've always found it rather, er, ironic that many of the people who rail against the almighty Consensus spend so much of their time trying to construct their own consensuses.

Witness the 400 "prominent scientists" recently touted by Marc Morano; the Oregon Petition; the creationist lists of scientists who accept the biblical account of how life came about; and so on and so forth. Does anyone doubt that, were the consensuses of denialists and cranks of whatever stripe somehow to become the mainstream, that these same people wouldn't vociferously defend their consensuses against all criticism?

The point I was trying to make in my previous comment is that this debate over consensus, while interesting on a purely academic level, is (I speculate) not approached in good faith by denialists and cranks. E.g. creationists try to chip away at the consensus on evolution so they can replace it with their own consensus, at which point they will stand on their heads and swear that Consensus Is Good.

Seen in this light, it's fair to say that getting well-intentioned people such as Orac et al to debate the finer points of consensus creation is no more than a political tactic, and there should be a space cleared in the debate to make political judgments of consensus critics.

I'm reminded of Harry Frankfurt's On Bullshit, in which he argues that bullshitters bullshit not to lie (they may indeed be lying, or telling the truth, they really couldn't care less), but to stake out political positions.

It's that political dimension I think scientists ought to be more aware of.

Citizen Deux: "But I am concerned that in the rush to come to consensus, something significant may have been overlooked. "

This has actually been a process over a couple of decades. See 'The Discovery of Global Warming' (http://www.amazon.com/Discovery-Warming-Histories-Technology-Medicine/d…)

This is why Orac wrote what he did - when one probes into the history, it's very clear that this wasn't a 'theory of the moment', but a possibility from way, way back which won by a slow accumulation of an overwhelming weight of evidence, from fields across the sciences.

A skeptic can only argue from data about physical reality. Any other type of argument is that of a non-skeptic. A skeptic may have a belief that is not supported by data, but that is not a skeptical belief. If you can't refute a well formed argument with facts and logic, then as a skeptic you may not refute the conclusion.

There is a very large difference between beliefs and actions. If one does not understand the data and science behind AGW, one can still take action to reduce and mitigate it because the adverse consequences (if correct) are severe.

But arguing about AGW with something other than facts and logic is not a skeptical position. One may refute unsubstantiated assertions (such as AGW is a vast conspiracy among scientists), but that is not an argument about AGW, but about AGW denialists who deny reality and impute motives in others with no data to support it.

> A skeptic can only argue from data about physical reality.

All evidence is to some extent processed - moderated through "non-physical" processes.

One can go to extremes and argue that the existence of physical objects is in itself very hard to establish. But even if we grant the "self evident" truth of one's immediate physical surrounding, scientific "data about physical reality" is heavily moderated.

Let's look at temperature records: You believe that some people built thermometers, others installed them in monitoring stations, and others still built computer databases that faithfully store the measurements collected from the monitoring stations. You use a machine that someone built, running software that someone wrote, to access the data. Believing the temperature records requires making assumptions about the credibility of the entire social structure.

Not only are you making these assumptions, you are not even stating them explicitly. Would that meet the bar of "arguing from data about physical reality"?

Thor Heyerdahl was treated as a crank for many years because of his theory that ocean travel was a possible means of diffusing cultural behaviour before Columbus. The scientific consensus was pretty brutal in their treatment of him. The scientific consensus was pretty brutal in their treatment of archaeological discoveries that could have lent support to Heyerdahl's thesis, for that matter. But he won the day--after 50 years.

This post doesn't take into account the possibility that the scientific consensus will use political or social tools rather than evidence to support an agreed position. We do see evidence of such behaviour in regard to SHS and AGW, specifically in regards to treatment of those who disagree.

When it was discovered that the British medical establishment invented 'safe' levels of drinking out of whole cloth, there was a minor furor, but two months later the government returned to formulating policy based on these invented levels. Incorrect consensus has consequences...

I think Arthur Clarke's observation that when a scientist tells you something is possible, it's probably true but when a scientist tells you something is impossible, it's probably false is something to keep in mind. I also think Planck's observation that sometimes one has to let a generation die off before a mistaken consensus is overturned is also germane to this discussion.

The consensus view has been proved mistaken too many times to sustain an argument for authority.

By Tom Fuller (not verified) on 29 Dec 2007 #permalink

Sortition, the thread is about being a "skeptic". If you want to be a skeptic about physical reality, that is fine, but you can't use different standards for what constitutes "data" for your own ideas than for someone elses ideas. That is "cherry picking".

Are you saying a skeptic should argue from something else orther than data and physical reality?

What is your idea of the alternative that a skeptic should argue from?

I'd like to offer an important note on the cognitive process whereby a scientist comes to accept a hypothesis. We all like to think that it's all a very logical process, and in fact most of it is a strictly logical cognitive process. But the crucial step of making the final judgement -- do I accept or reject the hypothesis? -- is not a logical process. That doesn't mean that it's voodoo or arbitrary or capricious. It is based on a different cognitive style that many scientists are uncomfortable admitting to. I'll call it pattern-based thinking. The funny thing is, pattern-based thinking is the original "style" of all nervous systems. Rationalism is, if you will, something of a pose. Getting a nervous system to think rationally is kinda like using a hand saw as a screwdriver -- you can pull it off if you hold it the wrong way and do everything just right. Some people are able to do this quite effectively but they're few and far between. And the decision to accept or reject a hypothesis cannot be made rationally. One uses logic to assemble all the pieces that go into the final decision, but that final decision is ultimately a matter of judgement, not logic. The decision that results cannot be rationally justified. This isn't to imply that such judgements are subject to challenge, but it does mean that we can't prove our judgements.

This is the factor that permits denialists to masquerade as skeptics. They insert into their judgement process some political or personal distorting factor, and then claim that their judgement is every bit as valid as anybody else's. If you accuse them of this, they simply throw the same accusation back into your face. Hence the standoff.

By Chris Crawford (not verified) on 30 Dec 2007 #permalink

No - I am not arguing against "physical data". I am arguing against the idea that there is "physical data" that is objective and can be relied upon, and then there other types of data (psychological or social, for example), that should not be relied upon. This is an artificial distinction that is not useful.

I think the most important characteristic of the skeptic is self doubt - being willing to re-examine every idea one holds.

Another reason to prefer evidence-based discrimination over consensus-based is to provide clarity when scientific consensus becomes difficult for the public to discern. Here, I refer to the So-called Complementary and Alternative Medicine (SCAM) community, which has made noticeable in-roads in replicating the hallmarks of science but without the science. Most countries now have SCAM-based professional societies, journals, colleges, clinics, product regulations and national health centres (e.g., NCCAM). True scientists should have no difficulty recognizing ruse from reality in this area, but public perception is increasingly challenged. The woo published in the National Journal of Homeopathy may be nonsense, but the public can mistake it as articles in a peer-reviewed academic journal. Health Canada may regulate a homeopathic product to cite "Level IV" evidence of a therapeutic claim, but not understanding this to mean reference to "homeopathic materia medica", the public may see this as a Health Canada endorsement of homeopathic efficacy. The fuzziness created by the SCAM community is causing skeptics to use the redundant term "evidence-based" medicine.

(Originally posted to Crooked Timbers. Probably should have been posted here)

If scepticism = deductivism (Popperian, for example), then it was pointed out long ago that the sceptic is biased towards conservative science. That's simply because old and established theories have survived more attempts at falsification, and should by this particular metric never be discarded in favor of newer theories which have greater PROMISE, but have yet to be thoroughly worked out.

This is more a problem for philosophers of science than scientists, because the latter don't pay any attention to the former when picking a theory to support.

This is a methodology and philosophy debate with a long history. Let's try framing it this way:
1) Scientific concensus does not cause a theory to be true
2) To the extent that a theory is a generalisation, establishing the truth of a generalisation is a logical challenge
3) Specific confirmations do not establish the truth of a theory (and they can only count as supporting evidence if they are the result of a failed falsification attempt) (yes, courtesy Popper there).
4) A single valid falsification immediately establishes the failure of the theory (but doesn't mean that in matters of pragmatism the old theory is not useful to the extent that it did work and still continues to work)
5) The consequence is that scientific concensus may result from the best available theory, or it may result from being unaware of (or denying) a valid falsification, or it may result from pragmatic adherence to a failed theory where a younger theory has not yet established useful working principles.

What challenges me in this is multifactor causality. What constitutes a valid falsification attempt when multiple factors can cause an outcome? Should we automatically rule that outcome out as being a valid falsification test? Should we seek a more specific falsification test?

I would be the first to acknowledge that the witty and literate readership of Crooked Timber is also more scientifically aware than most of the Webulace, just as Orac's technically savvy audience is also w. & l., etc.
But take a deep breath of this thread's bouquet, just to experience what a link from CT can do. Aaaahhh ... scientifically literate, witty, with just a soupçon of that special insolence that comes only from this region, it is a vintage to store in the cellar and uncork for some special occasion! When Orac is in top form, good things happen.

Steve LaBonne is on point in noting that

The fascination with the supposed injustice done to DDT is one of the more obscure and bizarre corners of antiscience wingnuttery.

One way to respond to James Fox is to point out that DDT production peaked before Silent Spring was published, its decline caused by increasing resistance to the chemical among the boll weevil and bollworm, that agricultural use was the primary cause of resistance, that Rachel Carson very likely saved millions of lives by hastening the ban on agricultural use of DDT, etc., etc. To respond in that way is natural, and tempting, and gives rise to many epic-length threads. But it never seems to lead to resolution (the way we hope that issues of fact can be resolved) because the point really being argued is not whether the ban on most commercial uses of DDT was wise from an objective standpoint of public health benefit vs. risk. It's whether environmentalists are ... well, evil.

... Rachel Carson is a classis example of the ongoing hubris of the "scientific" environmentalists that seem more than happy to relegate millions to a hideous death or blindness just to hold fast to a "consensus", and frankly wrong, notion that DDT use will destroy the environment.

In the context of a debate about the history of antimalarial efforts, such a statement is wacky and paranoid -- yet, similar things are said every day and taken very seriously by those of a certain political persuasion. Why? Because that political persuasion is the one which holds that governments, and especially super-governments like the UN, and extra-especially scientists who support them, should be viewed with deep suspicion. Within that debate, the statement is neither wacky nor paranoid, but simple common sense. And it has deep emotional appeal because it seizes the moral high ground believed to be claimed by the other side: "You care more about your precious 'scientific' consensus than you do about the lives of poor African children, don't you, you hypocritical bastards?" Feels good, doesn't it?

Returning, at long last, to Orac's theme, I think this is an example of the temptation we should be most wary of, lest we fall into pseudo-skepticism ourselves.
When someone offers me an argument challenging the conventional wisdom, and it makes me feel really warm and fuzzy inside, that's the time I hope I will ask to flip it over and read the fine print.

When someone offers me an argument challenging the conventional wisdom, and it makes me feel really warm and fuzzy inside, that's the time I hope I will ask to flip it over and read the fine print.

I do not specifically dispute this. But it seems to me that being offered an argument affirming the conventional wisdom that makes us feel warm and fuzzy inside should be considered just as dangerous.

In fact, I'd say it's the 'warm and fuzzy inside' part that should cause us to be extra skeptical, not whether conventional wisdom is challenged or supported.

By Caledonian (not verified) on 01 Jan 2008 #permalink

Steve LaBonne wrote: The fascination with the supposed injustice done to DDT is one of the more obscure and bizarre corners of anti--science wingnuttery. "jre" also wrote a lot on 12-31 but given the smear nature of his argumentation I'll try and avoid the temptation to discuss things on his terms except to say that the assertion that Rachel Carson very likely saved millions of lives is laughably unsupported by available facts. Also the obvious assertion that I think environmentalists are evil is an absurd conclusion from what I said in that my problem is with environmental fundamentalists that take their cause to the unscientific extreme. These fundamentalists seem to think man is clearly the disease and the resulting philosophy is that of Luditeism and some perverse need for everyone to regress to some kind of idealized tribal agrarian life to save the planet. This type of environmentalist presents him/her self as knowledgeable and with authority and loaded with facts that are all claimed to be proven, verifiable and established. This is a perfect example of necessary skepticism when the philosophy and politics of the one claiming authority is known to be fring, highly agended and odd.

Firstly one can not, to my knowledge, do an injustice to a chemical. However injustice has been done to millions of Africans. Also DDT is not used to combat internal human parasites. The current accepted practice is for DDT to be used to control mosquitoes that carry the parasite that causes malaria and does not involve broadcast spraying at all. This is done in a manner that does not get DDT into the environment and no, I repeat NO other chemical insecticide is as effective. This is not anti science or quackery it is sound biology, chemistry and social policy. Please show me your evidence, experiments, journal articles, reviewed documented field tests of any other chemical that could effectively control malarial mosquitoes as well as DDT. Again your statement appears to be nothing more than hubris and an arrogant repetition of something you heard elsewhere that fits into your narrow philosophical and political view point. I admit that I may be inaccurate in accusing you of arrogance and/or ignorance but your assertion that I dwell in the obscure and bizarre corners of anti-science wingnuttery fails at any level of intelligent discussion or argumentation. People are dying in Africa so that farms can maintain their organic certification in malarial areas to satisfy and feed the whole-food, all natural, wealthy , fashionably, arrogantly organic of western Europe.

The skeptic needs to be aware that consensus can be the product of fashion and not the end result of critical discussion about the established facts. Conclusions and consensus is not just the accumulation of data but the process whereby humans use judgment applied to known observable facts and theories. When humans are involved, feelings, emotion and even politics nearly always influence, to some degree or another, the process or the stated conclusion; and some of this influence may be generationally removed when it comes to the "tried and true" ideas of the now. Not recognizing this is the practice of a real wingnutter. (Please see Robbie's post of 12-31-07 above)

By James Fox (not verified) on 02 Jan 2008 #permalink

James, to review the bidding, your comment referred to

... environmentalists that seem more than happy to relegate millions to a hideous death or blindness just to hold fast to a "consensus", and frankly wrong, notion that DDT use will destroy the environment.

And now you're upset because I paraphrased that as "environmentalists are evil"? Pbbbbffft. I'll say it again. You have fallen under the sway of a particular flavor of pseudo-skepticism that believes in an environmentalist conspiracy to suppress the use of DDT for malaria control. It's hogwash. DDT resistance was observed in malaria-carrying mosquitoes as early as 1951, with Anopheles Sacharovi, in Greece, and the situation just got worse from there. It was DDT resistance, not some sinister environmental cabal, that caused WHO to switch gears on malaria vector control. Public health officials were committed then, and remain committed, to using the most effective tools to control malaria. DDT has never been banned for use against malaria -- the problem is that when you keep spraying it indiscriminately, it stops working.
Here are some resources for you.
EPA has just recently posted its DDT archives:
http://www.epa.gov/history/topics/ddt/
The best paper historical reference is Mosquitoes, Malaria and Man, by Gordon Harrison.
Bug Girl has an excellent series on mosquitoes and resistance. Start here:
http://membracid.wordpress.com/2007/06/13/ddt-malaria-insecticide-resis…
The best historical coverage by a blog is by Ed Darrell:
http://timpanogos.wordpress.com/category/ddt/
And the best overall coverage is by Tim Lambert:
http://scienceblogs.com/deltoid/ddt/

Why have these people spent so much time researching and reporting the DDT issue? It is because the "Rachel Carson killed millions" meme is really, really stupid. It's not bona fide skepticism, James, it is pseudo-skepticism. Now, I'll admit that I expect all this to bounce off you. You don't sound much like someone who is eager to find that he's wrong. But surprise me. Delight me. Do your own research, and reconsider your position. And next time you accuse scientists of being "happy to relegate millions to a hideous death", try not to get your feelings hurt when someone calls you on it.

Oh, and thank you, Caledonian. Your point is well taken. My focus on seductive contrarian arguments was motivated by my own impression of human emotional reality -- that is, that there's a special thrill that comes with believing oneself an outlaw, and that it's comparatively dull to be in the majority.

Hmmm... but we can also be afraid to diverge from the group consensus and seek the familiarity and comfort of conformity with others.

Figuring out why we are one way sometimes and another at others is probably very important... but I have no idea.

By Caledonian (not verified) on 02 Jan 2008 #permalink

Caledonian, being able to ignore consensus is the major feature of the autism spectrum disorders. It is my hypothesis that that is how and why they evolved.

The only time a brain can be configured differently is while it is growing, in utero. That is when the major neural structures characteristic of the ASD phenotype develop. The major symptoms of ASDs involved disrupted communication. I think that the developing brain in effect "trades" developing a "theory of mind" (useful for communication with other humans so as to better manipulate them) for a "theory of reality" (useful for understanding physical reality so as to better manipulate that via making and using tools).

Many of the greatest scientists have been on the ASD spectrum. I think the ability to ignore the scientific consensus when it is wrong is an absolute necessity for scientific greatness. Work-a-day scientists can work inside the existing scientific paradigms. Going outside them and beyond them when they are wrong takes the ability to ignore them when they conflict with reality. That is something that many work-a-day scientists simply cannot do.

Sorry for coming late to this discussion Orac, and thanks for the kind words. I always like hearing I'm right.

However I found this odd from Citizen Deux:

I find, for example, the Hoffnagle position - you oppose consensus therefor you are a crank - to be unreasonably strict. The degrees of strength of the null hypothesis are significant.

This isn't a correct restatement of my views. More accurately if you attack consensus as a concept it's a virtual guarantee you are a crank. If you attack consensus using data you might just be a run-of-the-mill scientist, because what many of us do every day.

It is the tactic of attacking the mere idea of consensus, as a way of denigrating scientific understanding of the world in general, that is so indicative of denialism. Case in point John West doing just this in Tampa Online. See the difference?

Excellent post. I only disagree in putting obesity consensus in the same category as spheric earth, evolution, holocaust, global warming, vaccines, and tobacco causing disease. There is scientific debate in the obesity field. Thus, in my humble opinion, a sound obesity skepticism must be possible, for instance about current weight and weight loss recommendations, body mass index values and the like, after an unbiased look at the data. This must be distinguished from obesity denialism with statements such as obesity being completely irrelevant to health, using cherry-picked data.

Re JRE's above comments:

Your cited sources are dated and inaccurate, I've checked them out and especially find "Bug Girl" unable to reasonable consider the human costs of her clearly political views. And while Bug Girl plays the skeptic card at every turn she is clearly driven by an agenda and not the simple evaluation of the facts and resultant real human decisions based on what is best for the people involved. Your other cited sources also do not hold up and simply contradict the more up to date information contained in the most recent WHO position paper. And while I've never proposed the practice of broadcast spraying of DDT it appears that you have an opinion of DDT based solely on the results of said broadcast spraying. It's the same logic that states we should ban guns because they killed so many people in WWI and WWII. The fear of DDT appears generally irrational and not based on facts, and in my opinion has very little to do with science and a lot to do with a consensus political pseudo-scientific points of view. (And saving Rachel Carson's precious legacy) Your inability to not see this is a curious and hopefully an anomalous little corner of your thought processes. Also citing a science blog written by a computer scientist is hardly a supporting piece of evidence regarding DDT use. The oft spouted fear of DDT seems very similar to the irrational fear of amalgam fillings, vaccines and nuclear power. All factually unfounded, based on faulty logic and a lack of compelling fact based argument with no correlation between the stated fear and actual known risk. I hold to my position because it seems the most reasonable based on the facts I've taken the time to research and based on the need to protect human life. If human life isn't important then I guess my views are of no account.

From the WHO:
http://www.who.int/malaria/docs/IRS/DDT/DDTposition.pdf
The use of DDT in Malaria Vector Control: WHO Position paper. (2007)

"The Convention has given an exemption for the production and public health use of DDT for the indoor application to vector-born-diseases, mainly because of the absence of equally effective and efficient alternatives..."

"It is expected that there will be a continued role for DDT in malarial control until equally cost effective alternatives are developed. A premature shift to less costly alternatives to DDT, without the strengthening of the capacity (human, technical, financial) of Member States will not only be unsustainable, but will have a negative impact on the disease burden in endemic countries. "

"DDT has a spatial repellency and an irritant effect on malaria vectors that strongly limit human-vector contact..."

"Insecticide resistance in malarial vectors has commonly resulted from the use of the same insecticide for crop protection. ... This direct exposure has resulted in the development of vector resistance in several parts of the world. Despite widespread and intensive application, significant levels of DDT resistance is malaria vectors have been limited to some vectors species and geographical areas. Since DDT use is restricted to public health activities, vector populations are no longer exposed to DDT through other applications, which further reduces prospects for selection spread of vector resistance."

" It is advisable to retain DDT for resistance management until suitable alternatives are available"

"DDT is still needed and used for disease vector control simply because ther is no alternative of both equivalent efficacy and operational feasibility, especially for high transmission areas."

I believe my premise to be factual and my views about the policy and actions based on this premise to be suitable and reasonable. I have no assumptions based on political or philosophical opinions except that humans are of value and worth saving from unnecessary death when possible. I did not come to my conclusion regarding DDT prior to doing some research, nor did I seek evidence to support a view someone told me to have. I have no hidden agenda or premise regarding environmentalists except when they spout unsupported garbage with no factual support. Nearly every argument I've read against the current restrictive use of DDT uses poor logic and argues from authority or supports a view with Non-Sequitar statements. Those opposed to the use of DDT argue from fear, emotion or the view that their opponents are usually some kind of right wing Nazi idiot. Again nothing that holds water and no supporting facts, and the most strident environmental opponents of DDT rarely rise above ad hominem attacks, ridicule and a faulty use of correlation. DDT is a tool used to fight Malaria in the same manner that chemo therapy is a tool to fight cancer. I suppose the toxic effects of chemo therapy should preclude it's use? Why be skeptical of the need to use DDT when the known facts indicate the judicious careful use of the chemical will save lives better than anything else around and will not have an effect on individuals or the environment???

Jre, your hope that I'll be enlightened and see the wisdom of your way reminds me of the Campus Crusaders who tried to save my soul in High School. I appreciate your sincere and earnest desire. However you can bet that If I travel to central Africa I will have fabric swatches soaked in DDT to place in any room I sleep in. I expect it will be more effective than all the arguments you can muster to keep the mozzies away.

By James Fox (not verified) on 03 Jan 2008 #permalink

For me, one of the dividing lines between skeptics and deniers is that tendency of the deniers to lump everyone they don't agree with as a conspiracy, and then refuse to accept any input from them that they don't want to accept. Holocaust deniers have their Jewish/Zionist conspiracy and reject uncomfortable evidence of the holocaust from any source, whether it be news reports of the trial, anecdotes from survivors or their rescuers or even reports about the Nazi's own records. They dismiss it all as propaganda. AIDS deniers and those who believe that immunizations cause autism have their BigPharma/Medical community conspiracy, and evolution deniers have their "Darwin's Religion" to oppose. Many deniers of anthropogenic global warming (that I've run across) don't even accept that temperature measurements, tree rings and ice cores have anything useful to say about climate--to them, it is part of the global warming conspiracy. Don't even get me started on the moon-landing deniers.

Another thing that I find that tends to distinguish the two groups is the relative reliance on either rhetoric or interpretation of evidence. In my limited experience, deniers tend to rely almost exclusively on rhetoric, philosophy and logic (specious, flawed or otherwise), while skeptics are more likely to mention actual evidence.

The denier group that I'm most familiar with is the evolution deniers. One of the ideas that they cling to is that speciation is impossible. They state that it cannot occur, they quote creationist's pronouncements that it cannot occur, some will even quote Genesis, while others spin words and thoughts in an effort to persuade readers of their conclusions. But I have yet to see any of them even reference a single piece of physical evidence that even indicates that there might be any mechanism by which speciation could fail to occur. Given the evidence that even I've seen or read about that supports the existence and mechanisms of speciation, I find the evidence-less rhetoric against it absolutely underwhelming.
Brownian, host blogger of www.humpday.com/brownian/ once wrote:

I once re-defined keeping an open mind to mean "not being afraid to reject an idea if there is no evidence to support it, no matter how much one wishes it were true."

I do not believe that deniers have this kind of open mind. A proper skeptic does.

By Dangerous Dan (not verified) on 03 Jan 2008 #permalink

Ah, James, you have taken a baby step toward understanding the subject, so I am pleased with your progress. Yes; as you've pointed out, WHO supports the judicious use of DDT for malaria vector control, acknowledges the continuing fact of DDT resistance among malaria-carrying mosquitoes, and notes that agricultural use of the chemical was a leading cause of that resistance. All true. Let's say it again:

DDT has never been banned, in the US or the rest of the world, for use against malaria. Agricultural use of DDT leads to resistance in exposed populations of insects, reducing its effectiveness against those insects. Strategies for combating malaria have evolved just as insecticide resistance has evolved, and they have become more effective as we have learned more about the disease and its vectors.

Glad we've gotten that far.
It would have been nice if you had given some serious consideration to any of the five reference sources I supplied you, but my hopes were not high, so I'm not disappointed.
To return to Orac's theme, the reason your argument (if that's the word) does not qualify as genuine skepticism is that you have bundled all your objections to what you perceive as the conventional wisdom on DDT into a hopeless mishmash of aggrieved feelings. I can't even parse it, let alone respond to it. If you really want to argue that the ban on agricultural use of DDT was unwise, then say why. If you believe that scientists or public health officials cheerfully countenanced the deaths of millions in order to preserve a mistaken consensus, then tell us who made the decision, and what it was, and why it was wrong. If you have a better approach for malaria vector control than the integrated pest management strategies outlined by Bug Girl, why then, let 'er rip! We are on the edge of our seats! But you can't credibly challenge the recognized authorities in this field without getting down to specifics. And so far, James, all you have given us is smoke.