Foundations of Skepticism: Extraordinary Claims…..
The oft heard battle cry of the charging skeptic, that extraordinary claims require extraordinary evidence, is much more than a debate talking point. It is, after the scientific method, the most important fundamental principle of the skeptical approach to understanding the universe. And despite what proponents of pseudoscience and supernatural belief systems might claim when confronted, that the skeptic is closed-minded and should accept lower orders of evidence, it really isn’t all that controversial.
Everyone incorporates the extraordinary evidence requirement into their daily lives, even the most ardent of believers. If, for example, I told you that I had a penny in my left jacket pocket, you would be unlikely to protest. This is a routine occurence after all. The claim of transporting 1,000 pennies in this fashion would likely lead to instinctive doubt and the visual inspection of my left pocket, looking for the telltale effect of their weight, but you would be unlikely to call out for more powerful proof. Were I to claim that I just so happened to be carrying a Faberge Egg around, you would certainly request that I put my money where my mouth is. The chance that I would have one of these immensely valuable and rare entities is extremely low and calls for more than the anecdotal testimony I had provided.
Another example, and one more in line with my particular expertise, is that of homeopathy. For those uninitiated in the history and practice of homeopathy, here is a quick review. Roughly 200 years ago a German physician named Samuel Christian Friedrich Hahnemann grew disillusioned with the practice of medicine. He was right to question the trends of the day, which included practices such as bloodletting and dosing patients with mercury based compounds. Pre-scientific medicine often led to a worse outcome than if no treatment had been provided at all. But proponents of these modalities, like pushers of complementary and alternative medicine today, based their beliefs on anecdotal evidence and were led astray, just as Hahnemann soon would be.
Hahnemann noticed that the untoward side-effects of taking quinine, one of the only truly effective medications of the day, were similar to the actual symptoms of the malaria it was used to treat. He decided, based on his equally pre-scientific understanding of nature, influenced by a hefty helping of magical thinking, that the ingestion of a substance which causes a certain set of symptoms in healthy individuals will cure those same symptoms in the ill patient. He then set out to uncover the true curative power of every natural substance he could get his hands on. By collecting countless anecdotal experiences from healthy volunteers, usually friends and family members, he catalogued the supposed effects of these substances so that he might match the right substance with the right symptoms in his patients. The results were quite comical, as would be expected with such a process, with each substance being associated with long lists of symptoms ranging from the typical, such as nausea, to the ridiculous, such as feeling chills only between certain hours of the day or dreaming of criminals. No attention was paid towards whether or not these symptoms were coincidence or a result of influence by Hahnemann himself.
Hahnemann went on to invent the notion that more dilute concoctions were more effective. This led to the absurd dilutions commonplace in homeopathy today, most of which lead to treatments containing no molecules of the original substance. So when a homeopath recommends the ingestion of Toxicodendron radicans to cure your itch, you have little to fear of an allergic reaction to the poison ivy in the bottle or pill because, well, there is no poison ivy in the bottle or pill. And when an over-the-counter homeopathic conjunctivitis cure has belladonna listed as an active ingredient, you don’t need to call your local poison control center. You may have thrown good money down the toilet but you probably haven’t ingested one of the most toxic plants known to man. Of course there are many preparations of homeopathic remedies sold with measurable amounts of the original substances, and because of lax laws regulating quackery in America, a topic for another post, you can never really be sure that the carpet matches the drapes. There are known examples of companies using the homeopathic label to avoid the prying eyes of the FDA.
Despite over 200 years of use, there has yet to be shown a beneficial effect of any homeopathic remedy for any condition in properly designed studies, and it is widely considered by scientists and physicians that homeopathy is no better than placebo. This should come as no surprise because, despite the 200 years since its discovery, the claims of “like treats like” and of increasing efficacy with increasing dilution have never made any sense on a basic sciences level. They have zero plausibility and proponents have resorted to claims of magical water memory and quantum physics as mechanisms of action for their treatments when confronted with reality. Homeopathy stands alone at the top of the crap pile that is alternative medicine.
So when someone offers up a homeopathic remedy to cure what ails you, it is not closed-minded to expect extraordinary evidence to support such claims any more than it would be to expect a peek at that priceless piece of artwork stuffed in the left pocket of my fleece jacket. I might be fooled. I might be lying. On a personal level, it works for me just doesn’t qualify. Placebo effects and other biases inherent in determinations of efficacy can easily account for such a belief. And when it comes to specific remedies proposed by individual practitioners or the companies who profit from their sale, collections of anecdotes and testimonials are not enough. And for something that violates fundamental laws of nature like homeopathy does, a few equivocal studies are meaningless. Even a few outright positive studies should not be enough to convince you. Homeopathy is as extraordinary as it gets and the evidence should be huge. It should be so blatantly obvious that to deny it would be just as crazy as it was to believe in homeopathy in the first place.
Not everything is as off-the-charts crazy as homeopathy of course. Some claims naturally have more merit or plausibility than others. And there is no universally agreed upon algorithm for just how much evidence is enough for each specific claim. But as a general approach, the expectation of better evidence for claims less likely to be true has served humanity well. Unfortunately however, the human brain is hardwired to work against us when it comes to the appropriate acceptance of ideas even as it is equally hardwired to continually come up with new ones, and we must strive diligently to avoid being fooled by ourselves. Examples of the negative consequences of failure to do so are all around us, from ignorant entertainers spouting harmful anti-vaccine rhetoric to Nobel Prize winning scientists championing bogus cancer cures. The skeptical community is growing faster than ever, and slowly gaining more influence, but it is an uphill battle at this point. But I remain optimistic about the outcome.