Anecdotal Evidence


When I said last time that postings would be infrequent over the summer, I didn’t realize that meant they would be non-existent.


But fear not, for as life’s complexities recede, I’ll be getting back to posting here at LogicCheck on a regular basis.


Returning to the summer, at one point during the last couple of months I was prescribed a medication and, being a high-information consumer, I took to the Internet to see what I could learn about it.


Most of the links that came up high in a Google search were for places like WebMD that provided background information on the drug, as well as lists of benefits and side effects. But one site offered reviews from individuals who had taken a specific med, providing the kind of user comments you might on an Amazon book page.


One such user/reviewer told a harrowing tale of how he had gone into cardiac arrest seconds after he popped the first pill of the drug I had just been prescribed into his mouth. While a critical-thinking mindset prepared me to trust my doctor over an anonymous poster to a previously unknown web site, guess which evidence was top of mind when it came time to down my first tablet of that same medication?


This is the power of anecdotal evidence, evidence based not on general facts or statistics, but on personal experience which is often powerful enough to overwhelm other sorts of evidence in terms of its persuasiveness.


In the case of my medicine example, fear that I might have an experience similar to the person who nearly died from taking the same medication had to be fought against through reasoning that persuaded me that advice from medical professionals and the testing procedures used by pharmaceutical manufacturers meant a drug released to the market was safe, even if it might cause the occasional disastrous reaction (presuming the original anonymous anecdote was true).


Like facts and statistics, anecdotes can play a useful role when presenting arguments for and against a position. For while facts and stats can be abstract and sometimes dry, anecdotes are stories about the experiences of real people, making them easy to identify with.


Putting aside the issue that anecdotes can be made up, a problem with true anecdotes is not the stories they tell, but the meaning they are supposed to represent.


Unsurprisingly, there is a Greek word for what an anecdote is meant to stand for: synecdoche (pronounced sin-EK-tokey) that translates to one thing standing in for another. In some cases, the substitution is simple, such as “Boston” subbing in for “the Boston Red Sox” when someone says: “Boston is going to win the World Series.” But, in the case of anecdotal evidence, a synecdoche often plays the role of the conclusion someone wants you to accept based on a piece of anecdotal evidence.


For example, did the killing of George Floyd demonstrate problems in police recruitment, training, and accountability procedures, or did it represent that policing itself was a corrupt and murderously bigoted practice? Either conclusion could be claimed as represented by the same event, the murder of Floyd, but neither is unquestionably supported by that anecdote.


Since Floyd’s murder, another controversy in the news has been the teaching of Critical Race Theory in K-12 schools which some outlets covered with stories of young children being made to feel uncomfortable or even humiliated due to their race. Presuming these anecdotes are true, do they represent that the American public education system has gone off the rails, or that some teachers may be implementing ideas likely to cause discomfort among children, and controversy among adults?


Given the serious consequences that can result from picking the wrong synecdoche, including legislative and judicial ones, it is incumbent upon us to treat anecdotal evidence with particular care, especially given the ability personal stories have to persuade, sometimes by overwhelming our reasoning through powerful tales with high emotional impact.


One way to do this is to treat a synecdoche as an argument, one that needs to be tested for validity and soundness.


For instance, the Critical Race Theory example I used to illustrate the synecdoche concept can be rendered into this one-premise argument:


Premise 1: Young schoolchildren are being made uncomfortable or even being humiliated in classrooms where teachers have incorporated principles of Critical Race Theory.


Conclusion: The American public education system is harming young children, not educating them.


As long-time logic-checkers will not doubt have noticed, there are a host of hidden premises that get you from that anecdotal premise to the conclusion. The most obvious one is a premise which says stories regarding excesses of Critical Race Theory are not limited, but widespread enough to use them as a basis to pass judgement on a national school system teaching millions of students.


Other hidden premises also need to be distilled from the original one-premise argument, and terms in the original premise and conclusion (such as “humiliated, ”harming” and even “Critical Race Theory”) need clarification if we are to avoid accepting a sweeping conclusion based on potentially narrow – if powerful – anecdotal evidence.


Given the human tendency towards biased and tribal thinking, we generally give anecdotes more leeway when they illustrate issues we already believe, such as the nature of the police or the public school system. This is why it is in our interest to ground our beliefs in more than one type of evidence.


Before looking at how to do so, I’d like to look next at one last form of evidence that packs a wallop without using a single word.