Monday, July 14, 2008

Anecdotes are like.....

“Facts are meaningless. You could use facts to prove anything that's even remotely true.”
-Homer

We are continuously bombarded with facts. They are, in fact, inescapable additions to our daily routine, lurking around every corner and entering our awareness in a variety of forms via myriad routes of delivery. We discover them in books and newspapers, have them shoved down our throats on infomercials or on local news reports, or simply pick them up from conversations with other primates.

It depends on the situation at hand, but the most common practice is to equate fact with reality, or more importantly with truth. For example, an evolutionary biologist may claim that the focus of their scientific endeavor is a fact, meaning it is accepted as something that exists or has happened as verified by an established means of scientific evaluation, naturally having something along the lines of molecular genetics or paleontology in mind. Of course, an astrologer might use the term in a similar fashion when he declares as fact that the position of celestial bodies enfluence whether or not you might get a raise or meet a mysterious, and handsome no doubt, stranger. Both believe themselves to be correctly using the term because what is an established means of evaluation, be it the scientific method or divination, is in the eye of beholder.

The following perceived facts have something in common:

1. "With my last bad cold, I tried Zicam and felt better immediately. Zicam works!"

2. "Every time I see a newborn who spits up, I switch them to soy formula and they improve. Lactose intolerance is a common cause of reflux in infants!"

3. I had a terrible feeling that something bad happened to my sister last night only to receive a phone call notifying me of her death. I am psychic!"

4. I eat at fine restaurants frequently and can always tell the difference between cheap and expensive wine. I have a highly trained palate!"

5. Every time there is a full moon, our unit fills up with mothers whose water has broken. The gravitational pull of the moon effects amniotic fluid like it does the sea!"

The common thread between these statements of fact is that they are anecdotes, the bane of any tried and true skeptic. Even for juggernauts of critical thought, like Harriet Hall and Steven Novella, standing up to an Oprah of anecdotes is often a losing battle because, instead of a reasonable evaluation of the available evidence, they rely on overestimation, overgeneralization, unfalsifiability, post hoc reasoning and, all too often, a hefty dose of emotion. Though the logical errors inherent in these examples may quickly become evident with even a superficial critical analyses, nevertheless they are more than adequate to convince thousands of believers.

Anecdotes are kryptonite to the skeptic, who relies on rational interpretations of the events that befall us. There is no variable in the equation for emotion. And while it may seem impressive that an individual's cold symptoms improved so dramatically after using Zicam, that observation in no way equates to proof of a causal relationship. It may only represent regression towards the mean, a common source of confusion for humans, who share a tendency to seek aid when symptoms are at their worst. This is especially evident in chronic conditions that are known to wax and wane in severity and is the very reason why use of a control group in studies seeking to discover the effectiveness of a treatment is so vital.

The powerful nature of anecdotal evidence, and the difficulty overcoming it, makes sense if one keeps in mind that the scientific method is a relatively new phenomenon, and scientific medicine merely a recent eye blink in the two hundred thousand years since modern humans diverged from one of the many twigs on the evolutionary bush. In the distant past, considerably farther back than the six to ten thousand years that make up human existence according to biblical literalists, there was a time when relying on the advice from another to not eat the red berries, for instance, was the only means of learning important and potentially life-prolonging information about our environment.

Another reason that anecdotal information fosters such a cognitive sticky wicket for skeptics is the innate human bias towards temporal relationships when defining cause and effect. Once again, this trate would have resulted in significant benefit thousands of years ago, when our earliest ancestors were more at the mercy of environmental pressures than the current state of affairs, but is now more of a hinderance outside of early childhood. This logical error, known as the post hoc ergo propter hoc fallacy, post hoc reasoning, or correlation not causation, is evident in most testimonials regarding unproven and implausible therapies.

The above example involving psychic powers being evident in the ability to know when a friend or relative is in harm's way is a classic example of yet another source of miscalculation in many anecdotes. The remembering of hits and forgetting of misses leaves the best of us vulnerable to erroneous beliefs whether in the realm of John Edwards style cold reading or deciding if a particular home remedy works. Yet another illustration of how fallible human memory can be.

This brief discussion merely scratches the surface but it is a good start. With this blog I hope to go into more detail on a number of topics vital to critical thinking, with a focus on pseudoscience and irrational approaches to healthcare. I also hope to have some fun and encourage reasonable discussion and debate.

4 comments:

Old Word Wolf said...

Excellent launch! I look forward to more.

The only problem is, sloppy thinking is so much easierthan critical thinking. You and I are baying at the moon; the moon doesn't listen. The cubs don't have the energy, training or inclination to be sketpics. That's a lot of work and sooo last century. Sigh.

Zoo Knudsen said...

Speaking from far too much experience, sloppy thinking is much easier because it often yields simple answers to complicated problems. Sick? It's just a blockage in the innate life force or a disturbance in your energy field. Confused? Don't worry, our religion has all the answers you need. Scared? All you need is a psychic cleansing of your rickety old house.

But to be quite honest, I'm not asking for anything that the majority of people don't already do when it suits them, such as when buying a new car or challenging a buddy's big fish story. We are all skeptics when it comes to certain things, it's just that far too many people these days have been born either with overactive credulogenes or have taken a few too many hits to their skeptic suppression genes. The big question is why there is such situational skepticism.

The Other Experiment said...

"The big question is why there is such situational skepticism."

Why? Because we are taught, from the time we are quite little, to believe stories of supernatural beings.

When ones brain is trained to accept the belief in something that cannot be proven (and be fed a bunch of guilt if we do ask questions), then why should any alarms go off in our brains when we hear non truths?

Zoo Knudsen said...

I think it goes deeper than that, down to something even more primitive than religion. I have no doubt that there are plenty of atheists out there that also accept a variety of pseudoscientific and/or paranormal beliefs.