Cognitive Dissonance and Evidence-Based Medicine

Cognitive dissonance is the emotional reaction to becoming aware that one holds two contradictory ideas or feelings simultaneously. It is a term from a rich area of cognitive psychology looking at how people derive and maintain beliefs. One of the best and most accessible works on the topic for the general public is Mistakes Were Made (But Not by Me) written by Carol Tavris and Elliot Aronson. The phenomenon of cognitive dissonance has relevance for the practice of  evidence-based medicine (EBM), as for most complex human endeavors, because it affects how we maintain old ideas and react to new ones.

One of the core principles of EBM is that due to a host of well-established factors both doctors and patients (or pet owners in veterinary medicine) often evaluate the effects of medical interventions inaccurately. Personal experience and observation, even by someone with extensive training and practice, is less reliable than controlled scientific study. The evidence for this is overwhelming, and a central reason for adopting the EBM approach is the acknowledgement that our common strategies for evaluating medical treatments are inferior. Unfortunately, but not surprisingly, telling people (especially doctors) this generates resistance, and sometimes hostility.

We generally view ourselves more positively than we view others. This extends not only to how we evaluate our own intelligence, attractiveness, and so on, but also how we evaluate our own objectivity, fairness, and rationality. When we are presented with evidence or argument that challenges not only the facts we accept to be true, but our own intellectual and personal qualities, cognitive dissonance comes into play. We tend to rationalize or outright reject our own mistakes, misperceptions, and errors partly because accepting them involves not only changing our beliefs about something else which is hard enough, but re-evaluating our beliefs about ourselves. (An excellent review of this topic is Emily Pronin’s paper How we see ourselves and how we see others. Science 320;1177-1180; 2008.)

Veterinarians (and MDs) are generally smart, conscientious people who genuinely want to provide the best possible care for their patients. And most of them likely see themselves this way. Most accept the general principles of EBM because they makes sense and are consistent with how they already see their work. Most doctors think they already practice EBM, despite data that show that not as much of conventional medical practice is founded on high-quality evidence as is generally believed (though certainly far more than CAM practices). Suggesting that they may be routinely mistaken about their diagnoses or therapies challenges this self-assessment, and this adds to the resistance to the conclusion. Research in human medicine shows much greater inconsistency and error rates among doctors then they themselves believe. There is no reason to suspect we veterinarians do any better in this respect.

One of the challenges, then, in promoting science-based medicine is to present the advantages of it in ways that minimize the dissonance and resistance that inevitably arise when the inadequacies of current practices are pointed out. When I criticize CAM or other approaches or attitudes within the profession, I am routinely accused of arrogance or of belittling the clinical experience of others. Of course, I feel I am simply advocating for a better and healthier approach to veterinary medicine, and my honest intent is to contribute to the growth and betterment of the profession. I have spent a great deal of time and effort evaluating the epistemological theory and the specific evidence for the subjects I discuss, and I think I have generally sound conclusions drawn from theory and evidence. But since I undoubtedly  have all the same cognitive weaknesses as everyone else, it is likely that sometimes I unskillfully or carelessly make my case in ways that are unnecessarily antagonistic. And it is likely that sometimes my conclusions are simply wrong.

There is a complex balancing act between acknowledging one’s own limitations and weaknesses while at the same time vigorously acting on one’s values and beliefs. The result is never perfect, but it is undoubtedly superior to unquestioning trust in one’s own intuition and experience. It requires personal and intellectual humility and also the converse, the willingness to confidently and assertively put forward one’s conclusions. And it is inevitable that EBM will generate resistance and controversy because it requires challenging and changing accepted practices, so one must be willing to be as honestly self-critical as possible yet still respond vigorously to such resistance.

In an odd way, the degree of cognitive dissonance one encounters is perhaps greatest when one is challenging approaches in the gray zone between established science-based medicine and outright CAM. Subjects I’ve addressed previously, such as probiotics, are ideas based on sound scientific principles and supportive preliminary laboratory data, unlikely clearly unscientific practices like homeopathy. And yet, when they are put into practice, usually as commercial products, before there is sufficient evidence to support such use, these ideas fall into conflict with the principles and practice of EBM. Yet because of their underlying plausibility and relationship to established medical practices they are often quickly accepted by veterinarians and doctors who have a generally scientific medical philosophy. These clinicians, then, are especially resistant to the suggestion that they are not adhering to their stated scientific values when they justify using such approaches because in their personal experience they seemed to have helped individual patients. Unlike the dedicated alternative medicine provider, who can always reject evidence by casting doubt on the relevance of science to what they are doing, doctors who support EBM in principle may experience cognitive dissonance when such gray-area practices are questioned.

The following are some excellent resources for investigating more deeply cognitive dissonance and the inevitable limitations and weakness in human reasoning that require us to rely on science to more closely approach a reliable understanding of reality, in medicine and life generally.

Don’t Believe Everything You Think: The 6 Basic Mistakes We Make in Thinking by Thomas Kida

Snake Oil Science by R. Barker Bausell

Predictably Irrational by Dan Ariely

On Being Certain: Believing You Are Right Even When You’re Not by Robert Burton

The Drunkard’s Walk: How Randomness Rules Our Lives by Leonard Mlodinow

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