This perspective from a clinical physician nicely illustrates the tension between learning from science and learning from direct experience.
When I entered medical school in 1997, I joined a generation of doctors that was supposed to practice evidence-based medicine. First in small groups, and later during clinical rotations, we learned to interpret the medical literature and apply the conclusions of randomized, controlled trials to our clinical decision making. Working within this new paradigm, we were going to rise above the apprentice-based training of our forbears and make decisions on the basis of gold-standard, Level I evidence.
The scientific clinician. Huzzah!
But real life has intruded on the carefully catalogued odds ratios that I memorized as an intern. I’ve come to appreciate that the influence of a randomized, controlled trial — no matter how well conducted or generalizable — pales in comparison with that of the audible bleeding of a profound postpartum hemorrhage. As I tell residents and fellows, in the human mind, adverse anecdote — what I’ve come to call Level IV evidence — is more convincing than even the tightest of confidence intervals.
You always trust your own experience more than data. Persuasion counts on that.
Randomized, controlled trials may be the gold standard, but their results can take decades to make their way from the pages of peer-reviewed medical journals to actual effects on routine care. Adverse anecdote can transform a clinician’s practice patterns in an instant.
The well told story, the compelling anecdote, the flashbulb memory – whatever you want to call that powerful single experience – is perhaps the strongest persuasion play of all. If you can design a Box that provokes an intense memorable, sensory, and affective response, you can create a Change that it is extremely difficult to change.
The easiest example for me to offer explodes out of Dissonance. Make people think they freely chose a path that leads to self relevant, but aversive, consequences and that collision will produce some of the largest and most enduring change you can find in the persuasion and influence literature.
Now, let’s pivot off this personal anecdote to the larger context: Changing medical practice. John Ioannidis, with his colleagues, continues his one-man crusade to get physicians to act more scientifically. We’ve consider Ioannidis’s work before with his investigations of Scientific Science and he now shifts his view to how physicians and medical science resist, of all things, science. Ioannidis asks medical science to consider how much practice is unproven, yet persistent. He considers how often medical science tests the commonplace.
Rarely, some investigators find the courage to test established “truths” with large, rigorous randomized trials. When this happens, empirical evidence suggests that “medical reversals” may be quite common. In an evaluation of 35 trials that were published in a major clinical journal in 2009 and that tested an established clinical practice, 16 (46%) reported results consistent with current beneficial practice, 16 (46%) reported evidence that contradicted current practice and constituted a reversal, and another 3 (9%) were inconclusive.
Please re-read the last sentence in that quote. In those 35 scientific tests of established practices, nearly half disconfirmed the practice, finding instead evidence of harm or no effect. One might scientifically challenge this evidence, noting it’s not a systematic review and focuses only upon research published in 2009. But, if you’re sharp enough to raise those concerns, how do you understand a field that calls itself scientific, yet can find at least 16 standard practices that are worthless? Maybe these are the only 16 rituals and by dumb luck they were all tested and published in the same year.
Or maybe you can see the persuasive power of personal experience as revealed in the opening example of this post. See this tension, too, in the recent and on-going uproar over the value of various medical tests as with prostate cancer. You’ll recall that a US Taskforce decided against routine screening for prostate cancer, citing a considerable number of gold standard RCTs as contrary evidence. Then, the unsurprising chorus of disagreement from physicians who found their experience more compelling than the scientific review of that Taskforce.
You see the primary clash between persuasion and science, between human nature and falling apples in these examples. People who aspire to science constantly find themselves trapped by their human nature as especially illuminated through persuasion science. They have a field committed to science that conducts standard practices that are worthless at best and sometimes harmful at worst. When confronted with large, careful, and public disconfirmations of those practices – as with the prostate screening example – they find narrow exceptions, errors, and inaccuracies and drive through the truck of their personal experience.
You can feel a wind of warning here. Where do you fail to follow your science and instead persist with what you know best and trust most, your experience? But, more importantly, understand how your knowledge of persuasion science aids your development as a scientist. The science of persuasion describes and explains why science resists itself.
Human nature always forgets falling apples until the fruit falls upon it.