I was reading my recent issue of Scientific American (August 2008) and came across Michael Shermer’s opinion column, “Skeptic,” entitled “Wheatgrass Juice and Folk Medicine.” Other titles/subtitles I found on the Internet were:
“How Anecdotal Evidence Can Undermine Scientific Results”
“Why subjective anecdotes often trump objective data”
The column may still be online:
http://www.sciam.com/article.cfm?id=how-anecdotal-evidence-can-undermine-scientific-results I accessed it on 25 July 2008.
Writing about a controversy over the possibility some vaccinations cause autism, Shermer alludes in passing to what he appears to believe is the evolved pattern of reasoning our brains use that gives greater weight to anecdotal evidence than to scientific evidence.
“. . . we have evolved brains that pay attention to anecdotes because false positives (believing there is a connection between A and B when there is not) are usually harmless, whereas false negatives (believing there is no connection between A and B when there is) may take you out of the gene pool. Our brains are belief engines that employ association learning to seek and find patterns. Superstition and belief in magic are millions of years old, whereas science, with its methods of controlling for intervening variables to circumvent false positives, is only a few hundred years old.”
My mind leaped to agree with this because the trumping power of anecdotal evidence over research-based conclusions has always frustrated me in my dealings with decision makers on education issues. Additionally, I found Shermer’s characterization of our brains as “belief engines” delightful. Unfortunately, I suspect the reasons for my delight would chagrin him. Finally, my life experience has led me to believe the brain is hard wired to “make meaning,” so I thought, “This guy’s a genius; he agrees with me.”
His conclusions about why our “evolved brains” . . . “pay attention to anecdotes” seemed compelling at first, but after further thought, they appeared to be undercut by his own supporting assertions. I understood him to say millions of years of superstition and belief in magic have evolved brains with a predilection to see cause and effect where it may not exist because “false positives” are benign. He goes on to assert that failing to see cause and effect where it does exist “may take you out of the gene pool.” The assertion he assumes is that through natural selection our brains developed as "belief engines," seeing connections and making meaning even when there was nothing to see or understand.
Does this mean false negatives are deadly?
Is he saying our “belief engines” have served the species well for millions of years only because of the slight statistical advantage we gain by frequently perceiving connections that cannot be supported by science, and in fact do not exist?
Then is he saying “science, with its methods of controlling for intervening variables to circumvent false positives,” a method of decision making “only a few hundred years old,” is somehow to be preferred?
Also he appears to assert that science can distinguish conclusively the true from the false positives, the true from the false negatives and free us from millions of years of superstitious reasoning. Suddenly, the superstitious reasoning that has been evolutionarily successful for us as a species is now unacceptable and should be replaced by scientific reasoning.
Even if I were to stipulate to every thing he said: his assertions about superstitious belief, his apparently logical assertions that false positives are benign, that false negatives are evolutionarily deadly, and his assertion my brain, my belief engine, evolved in a way that makes it prone to believe things that that do not exist; even if I were to accept all of this as true I’m not sure I would be willing to replace my belief engine with scientific skepticism.
The conclusions of science are always subject to modification, change, even total reversal when new data is discovered or old data is reinterpreted. As I understand it, science never, by its essential nature, claims infallibility. The short few hundred-year history of science would refute such a claim.
Shermer appears to assume the superiority of scientific beliefs over any superstitious beliefs even though science is subject to error and expends no small part of it’s energy pointing out what it reasons to be “false negatives” (based on current data, subject to change). I can’t embrace the assumption that scientific beliefs are superior. It sounds too risky. After all, false negatives are deadly.
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