When debating with believers, I often encounter resistance to the idea that anecdotes are of little or no value as evidence of the efficacy or existence of something. From homeopathy to ghost sightings, the word of Uncle Bob or My-Friend-Marie-Who-Is-Not-Stupid is far superior in the mindsets of most than a peer-reviewed study or a meta-analysis.
Thatâ€™s perfectly understandable of course, for myriad reasons. For one, most people are not educated in the scientific method and so have simply never been taught the difference and values of types of evidence. Another reason is that weâ€™re hardwired to listen to our peer groups and accept word-of-mouth endorsements or warnings: â€œdonâ€™t eat the red berries, they make you dieâ€. A third and more sinister reason, particularly when it comes to medicine, is that science is often painted as â€˜unnaturalâ€™ and the alternative therefore better (and by extension, more effective. If illness comes directly from nature then so should the cure). Yes, itâ€™s a nonsense argument, but an all-too-common one.
So what should we do when a supposedly educated person posits a single anecdote as evidence for the effectiveness of alternative therapy in treating cancer? This is an exchange that happened last weekend as my husband and I were debating alternative medicine with a â€˜true-believerâ€™ PhD student:
Believer: â€œMy friend had cancer and rejected chemotherapy and drugs in favour of a special diet. He killed the cancer and is just fine now.â€
Tkingdoll: â€œCancer is more complex than that story allows. For example, it can go into remission by itself. You have no way of knowing if your friendâ€™s cancer went away because of the special diet or if it would have gone away anyway. Studies show thatâ€¦â€
My husband (interrupting) â€œMy friend also rejected medical treatment in favour of the special diet. She died. Painfullyâ€
At that point I shut up because I realised that my husband had, in this particular scenario, the far superior debating tactic. His story (a true one, I hasten to add) is extremely powerful because it warns the believer that the alternative therapy can be lethal too, where previously he may only have been exposed to his friendâ€™s â€˜miraculousâ€™ recovery.
It seems to me that if someone can be swayed by an anecdote supporting a position, then another anecdote for the opposite position should at least give them pause. We already know that person responds well to personal testimonials, so why not speak a language they know and like? The next time youâ€™re in a debate with a believer, particularly over something as important as life or death, try changing tactics. Instead of countering their anecdotes with your references to empirical evidence, simply throw down a story of your own.