NCrissieB wrote an excellent series of diaries about the anatomy of conspiracy theories, and the various psychological motives behind them. The whole series is worth reading to understand the motivations that underly various pseudoscience movements.
I am going to supplement this with an overview of something a little more applied: the actual tactics of denial movements, the stunts they employ, the arguments they use, the strategies for disseminating their literature. I hope this will come in handy the next umpteen billion times you encounter some nut on the Internet.
As the title says, I'm not exactly going to talk about conspiracy theories, but "denial movements". Practically speaking there is huge overlap between them: denial movements usually imply daffy conspiracies, and conspiracy theories often center on denying some historical or scientific consensus.
A denial movement is basically a pseudoscience or pseudohistory movement that attempts to deny a well established scientific of historical fact. This includes creationism, Holocaust denial, global warming denial, the denial of a link between HIV and AIDS, moon landing denial, and 9/11 "no plane" or MIHOP trutherism. Although deniers hate to be compared to other deniers, all of these movements have a lot in common from a tactical perspective. They all have an impossible denial goal, and have evolved very similar strategies of indoctrination and evading direct scrutiny.
Denial movements are almost always ideologically motivated (counterexample: moon landing denial) and it is often very difficult to tell if the deniers really believe their own stuff, or are purposely trying to throw a wrench into our body of knowledge for ideological gain. They will often argue with the passion and dedication of a true believer, but employ arguments and tactics that are dishonest on their face and appear premeditated. This has earned creationists the disparaging term "liars for Jesus," for example.
I personally think "denial movement" is a better description for many conspiracy theories than "conspiracy theory," because it emphasizes that these are not simply beliefs, but active efforts to push ideas on the population at large. Creationism isn't simply something people believe, but an effort to publicly discredit science and remove it from textbooks.
[Note: at least one of these denial movements is banned from Daily Kos. I think it's pretty obvious I'm not promoting any of them, nor does my diary grant them any useful exposure.]
Tactic 1: Argumentoids
An "argumentoid" is a very short piece of rhetoric, often one or two sentences, which gives the impression of a logical or scientific argument to the unwary. They must be short and easily understood and repeated by the layperson, for their purpose is to spread memetically among the general population.
Here are some examples of argumentoids I found in the wild over many years:
- (creationism) "Halley's comet loses material every time it passes the sun, which will reduce it to nothing in ten thousand years. So the Earth can't be billions of years old or Halley's comet wouldn't be around anymore."
- (holocaust denial) "The estimate of the Jews killed at Auschwitz was lowered by 3 million in the 1980s. So half of the Holocaust was just a clerical error."
- (ozone layer denial--remember these guys?) "A single volcanic eruption can dump more chlorine into the upper atmosphere than all the spray cans and AC units in the world. Surely a massive jet of chlorine launched from the top of a mountain at 100 miles an hour is more likely to be the problem then the hiss from your hair spray?"
- (9/11 denial) "Molten metal was found in the base of the trade center towers. But jet fuel doesn't burn hot enough to melt steel."
- (global warming denial) "If an iceberg melts it doesn't raise or lower the sea level, because of Archimedes principle---a floating object displaces its equivalent volume of liquid water. You can verify this yourself with an ice cube and a glass. So a temperature increase will not drown our coastlines."
Virtually all argumentoids have two major organs: a possibly false factoid as a premise, and an invalid argument that is almost always unspoken. This missing middle piece helps to make the line both tiny and deceptive. Here's a dissection of the previous examples:
- (creationism, Halley's comet)
Factoid: that Halley's comet will dissipate in 10000 years.
Unspoken argument: that Halley's comet was orbiting the sun at the beginning of the solar system, at roughly its present size.
- (holocaust denial)
Factoid: that one estimate of Auschwitz victims was lowered by 3 million people.
Unspoken assumption: that this estimate was actually included in the figure of 5-6 million Jews agreed upon by historians, justifying a subtraction. (In fact there was a bogus estimate produced by the soviet union, but it was never included in historians' accounts of the dead.)
- (ozone layer denial)
Factoid: that volcanoes emit ozone-depleting chemicals at greater volume, altitude and upward velocity.
Unspoken assumption: That natural chlorine is comparable to man-made CFCs. Natural chlorine is soluble and stays in the troposphere; CFCs are bad precisely because nothing reacts with them to keep them from entering the stratosphere.
- (9/11 denial)
Factoid: that glowing red metal found at the base of the WTC towers was truly molten.
Unspoken assumption: that the fuel fire was the only thing that could have heated that metal. The real source of energy was the collapse itself, not the fire that triggered it---just by standing, the towers stored about a trillion joules of energy, most of which was released as heat in a matter of seconds.
- (global warming denial)
Factoid: that an iceberg doesn't change the water level as it melts (pretty much true, but not exactly for a freshwater iceberg floating in saltwater.)
Unspoken assumption: that the world's ice is floating, rather than sitting on land, for example the continent of Antarctica.
Notice that in all of these arguments the premise has at least a grain of truth, but is pretty much a non-sequitur. The chlorine output of volcanic eruptions may be big, but it doesn't have anything to do with the price of tea in China. Neither does the flame temperature of kerosene, nor the rate of loss of Halley's comet. The real meat of the argument is the carefully unspoken implication, which attempts to connect an irrelevant fact to an unwarranted conclusion---and which is often dumb enough that it automatically debunks itself when spoken aloud.
However, these factual premises give the argumentoid a pseudoscientific quality. Deniers can make their argumentoid look more solid by digging up encyclopedia references and experimental data to bolster the first sentence. This gives an impression of scholarship and of a strong line of argument.
Argumentoids betray a bit of the strategy of denial movements. It is very difficult for the claims of deniers to end up in mainstream sources of information; they must make their own creative channels of dissemination. Deniers have been known to invent their own fake scholarly journals (global warming deniers invented the Journal of American Physicians and Surgeons, Holocaust deniers invented the Journal of Historical Review.) They have found creative ways to bypass editorial controls, for example publishing their literature by purchasing ads in college newspapers. They also embrace subcultures and grass-roots propagandizing, percolating their claims through the aquifer of everyday conversation rather than the stream of encyclopedias or textbooks.
To accomplish this, denial movements have either designed or evolved this very simple type of bogus argument, perfectly suited to spread among populations. Rather than being broadcast by its author, the argumentoid is able to pass like gossip among all who hear it, to be repeated in newspaper columns and sermons, to be spread from blog to blog. It is simple enough to spread faster than it can be eradicated.
One nagging question among fringe-watchers is whether these arguments were purposely designed. Sometimes an argumentoid seems intentional, and sometimes it comes across as a classic misunderstanding of physics. I'd say that many are invented by innocent mistake, but those who collect and disseminate them are often aware that they are false.
If someone whips out one of these argumentoids, what is the best way to respond? A problem with argumentoids is their hyper-simplicity: if you try to explain why they're false, your response is almost guaranteed to be longer, more boring, and less transparent. It takes some surgical skill to behead an argumentoid in one clear sentence.
Our anatomy suggests that you should avoid scrutinizing the premise. If it's a little false, for example if they name the wrong volcano, wrong year, or neglect the impact of salt versus fresh water, correcting this doesn't deflect the basic thrust of the argumentoid. Rather, one must identify the unspoken implication and show in simple terms why it is absurd. One trick is by humorous retort---back to the examples:
- (creationism, Halley's comet) "I'll be dead in 200 years. So the Earth can't be more than 200 years old or I wouldn't be here now."
- (ozone layer denial) Volcanoes have also launched way more metal into the sky than all our rockets combined. So I guess all those communications satellites can't be man-made.
- (9/11 denial) I lit an M-80 in my hand with a match, and blew off three of my fingers. But according to the Internet a match can't possibly burn hot enough to melt fingers.
- (global warming denial) Hi, I tried to verify your ice-cube experiment myself, but I can't get an ice cube: I live on land, and supposedly all the world's ice is floating in the ocean where it will do no harm. Can you FedEx me an ice cube from your oil platform? Kthxbye.
This isn't always the best approach. I'd try it only if the underlying argument is silly enough to ridicule, and it takes less time than directly explaining what's wrong with it. I'd say 1 and 3 are shorter than direct explanations; 2 and 4 are not worth snarking about.
Ultimately the best approach is for a scientific community to put together a collection of pseudoscience "baseball cards," summaries of individual argumentoids, their fallaices, and responses to them. Several websites have arisen to combat various denial movements, and some of them are laundry lists of argumentoids and their dissection. Phil Plait of Bad Astronomy has a decent roster of moon-landing argumentoids; the talk.origins archive has an extensive collection of creationist arguments, along with responses. This may ultimately be the best weapon against these rhetorical virii.