Vested Interests and Their Influence on Physicians- New Understanding from Cognitive and Social Psychology

Evidence-based medicine proposes patient care decisions based on the best evidence from critically reviewed clinical research, knowledge of biology and the biopsychosocial context, and patients' values and preferences.  Yet physicians often fail to make evidence-based decisions, despite many efforts to educate, or incentivize them to do so.  We used to think that the main reason was physicians' lack of knowledge and understanding of EBM, and human cognitive limitations that make such evidence-based thinking difficult.  However, now we realize that physicians are deluged by  attempts to influence their decisions so as to favor vested interests, whether or not that is good for patients.

We have discussed various kinds of deception used in marketing meant to increase physicians' prescriptions for drugs, and recommendations for devices and health care services.  Physicians have not proved to be very resistant to these methods.

Now a new article provides a different perspective on how marketers use cognitive and social psychology to manipulate physicians.(1)  Sunita Sah's and Adriane Fugh-Berman's introduction stated,

Physicians often believe that a conscious commitment to ethical behavior and professionalism will protect them from industry influence.  Despite increasing concern over the extent of physician-industry relationships, physicians usually fail to recognize the nature and impact of subconscious and unintentional biases on therapeutic decision-making. Pharmaceutical and medical device companies, however, routinely demonstrate their knowledge of social psychology processes on behavior and apply these principles to their marketing. 

The article then listed a number of findings from social (and cognitive) psychology that marketers may use to their advantage on naive physicians.

Psychological Mechanisms Promoting Acceptance of Conflicts of Interest and Dubious Marketing Ploys

First, marketers may take advantage of cognitive biases and psychological mechanisms that allow physicians to accept marketing maneuvers while denying the effect of marketing on their decision making.

Confidence and Over-Confidence

People are strongly influenced by messages delivered with confidence and do not take the trouble to ascertain the accuracy of these messages if doing so requires effort or money.

I would add that many humans, including physicians, are also over-confident in the accuracy of their own judgments.  (In 1989 we showed  that physicians often were excessively confident in their judgments of patients' outcomes, in particular, about survival of critically ill patients.)(2)

Of course, marketers often state their messages with great confidence regardless of their accuracy.

So physicians need to try to restrain their own over-confidence, and be more skeptical of the confidence of others. Maybe this would just be an exercise in simple humility.

Self-Serving (or Ego) Biases

People tend to believe that the results of their decisions, or of their groups' decisions, are better than average.  This can be called the Lake Wobegon effect (from Garrison Keilor's fictional town in which all the children are above average.)

We and others have shown that physicians may be overly optimistic about the outcomes of their own (versus others') patients, or their clinical units' (versus others') outcomes, again in the context of predicting survival of critically ill patients.(3)  We have also posted about how corporate boards of directors seem to almost always think that their hired executives are better than average, at least when determining their executive compensation.

Similarly, Sah and Fugh-Berman wrote,

Physicians believe that their own prescribing behavior is unaffected by industry influence, although they concede that other physicians are susceptible to such influence.


Social psychology research confirms that people have a 'bias blind spot,' namely, they are more likely to identify the existence of cognitive and motivational biases in other than in themselves.
But, as Dana and Lowenstein wrote,

It cannot both be true that most physicians are unbiased and that most other physicians are biased.

So, to put it bluntly, physicians ought to be more humble about their own ability to resist outside influences and the resulting biases. Again, some simple humility might help.

Cognitive Dissonance

Sah and Fugh-Berman pointed out that

While articulating and believing in the importance of scientific objectivity, physicians' biases to accept industry gifts create cognitive dissonance; that is, discomfort that arises from discrepancy between conflicting beliefs, or between beliefs and behaviors.


Cognitive dissonance theory specifies three methods - not mutually exclusive - by which people manage or reduce dissonance.  Changing one of the dissonant beliefs, opinions or behaviors (possibly a difficult or painful process that requires sacrificing a pleasurable behavior or treasured belief); Lowering the importance of one of the discordant factors which can be accomplished by denial - forgetting or rejecting the significance of one or more of the conflicting cognitions; and adding consonant elements that resolve or lessen the dissonance (this may involve rationalizations to buffer the dissonance between conflicting cognitions.)

Physicians may use denial and rationalization to reduce cognitive dissonance caused by their concurrent desire for relationships with marketers and others with vested interests on one hand, and their professionalism and its obligation to put patients' needs first on the other hand.  Sah and Fugh-Berman cited Chimonas and colleagues,

Denial included (a) avoiding thinking about the conflict of interest; (b) rejecting the notion that industry relationships affect physician behavior, and (c) disavowing or universalizing responsibility for problems that arose from conflicts of interest ('there's always a conflict of interest...').  Rationalizations included (a) asserting techniques that would help maintain impartiality and (b) reasoning that meetings with drug reps were educational and benefited patients.

We have discussed various public justifications for accepting conflicts of interest by physicians and other health care decision makers that employed a variety of logical fallacies along these lines.

So physicians need to re-examine their treasured beliefs and the gratification they get from relationships with industry (as opposed to those with patients, colleagues, friends and families).  They could remember the advice that no one can serve two masters.

Sense of Entitlement

Physicians' sense of entitlement, especially given the increasing stress upon them, may be used to rationalize relationships with drug, device and biotechnology companies since these corporations seem to be among their few friends (versus insurance companies, government agencies, and sometimes hospital administrations whom physicians feel may be more burdensome.).  So, in one study,

Implicitly reminding physicians of the burdens of medical training and their working conditions more than doubled reported willingness to accept gifts....
So physicians need to reconsider that to which they feel entitled.  This is the third instance in which some humility might help. 

Principles of Influence Used by Marketers

Markets seem to also be well acquainted with the six principles of influence and persuasion identified by Cialdini and colleagues.


The norm of reciprocity - the obligation to help those who have helped you - is one of the guiding principles of human interaction

This is the foundation of the effect of relatively small conflicts of interest, such as giving of small gifts.

Physicians pay off industry gifts through changes in their practice


Gifts associated with a subtle implicit request may be more likely to achieve compliance than gifts that call for explicit reciprocation. 
So physicians need to be wary of Greeks, or anyone else bearing gifts, even those less conspicuous than wheeled horses.

Commitment and Consistence

Consistency is highly valued in our society and associated with rationality and stability.  After committing to a decision or opinion, people justify that choice or opinion by remaining consistent with it.

So marketers try to get physicians to make small commitments to leverage larger ones.  This is

why drug reps, ask, for example, 'will you try my drug on your next five patients?'
So physicians should remember there is no virtue in commitment to erroneous beliefs.  "A foolish consistency is the hobgoblin of little minds." - Ralph Waldo Emerson

Social Proof

This is basically the deliberate deployment of the logical fallacy of the appeal to common practice.

Social proof, also referred to as social validation or conformity, is the practice of deciding what to do by looking at what others are doing.


If accepting industry gifts is a cultural norm in medicine, physicians will continue to do so.  The opinions of colleagues are often used by industry representatives to sway physicians to adopt a particular therapy. 

This may be why industry works so hard to sign up health care academics.

Trainees in an institution, for example, are affected by the institution's stated policies but also - and sometimes more so - by what they see their mentors do.
So physicians, who often pride themselves on independence, need to be skeptical about the need to follow the crowd.

Liking or Rapport

The more you like someone, the more you are apt to follow their advice, even if your feelings towards them have been manipulated.

This is obviously why drug representatives, for example, are so nice to physicians.

Physicians often feel overworked, underpaid, and unappreciated [ed note -  and their is plenty of evidence, some of which we have discussed on this blog, that this is not unreasonable.]  Drug reps dispense sympathy, flattery, food, gifts, services and income-enhancing opportunities and seek to ask nothing in return but scholarly consideration of the benefits of drugs.
So physicians need to reconsider who really are their friends, and be skeptical of "friends" with something to sell. 

Authority and Security

This is basically the deliberate deployment of the logical fallacy of the appeal to authority.  The best example is industry's efforts to recruit key opinion leaders, that is health professionals who are perceived as authority figures, but have really been hired to market.

From an industry perspective, the best KOLs radiate status and authority while successfully convincing their peers (and perhaps themselves) of their illusory independence and lack of bias.

Note that

KOL speakers not only influence audience members' prescribing behavior, but also - as predicted by cognitive dissonance theory - become more convinced themselves of the benefits of the products they endorse.
So physicians need to be skeptical of those claiming to be authorities, especially when they are connected with people who have something to sell.


We used to strongly believe (and Dr Wally Smith and I used to teach a course to the effect that) the major barrier to true evidence-based practice was the cognitive limitations that physicians share with all humans.  We thought in terms of cognitive biases and the inappropriate use of cognitive heuristics leading physicians to inaccurately judge the probabilities of diagnoses and medical outcomes, and thus make less than optimal decisions.

Now it seems apparent that the deliberate influencing of health professionals' judgments and decisions by external actors, mainly those interested in selling more products and services, but sometimes by those with ideological or political motives, is currently a much more important challenge to evidence based practice.  It looks like the influencers may be very knowledgeable about human cognitive limitations and how social psychology influences judgment and decisions, and may use this knowledge to pursue their vested interests, at the financial and physical expense of patients, and ultimately the public.

 True health care reform would encourage professional education designed to increase resistance to external influences that put self-interest ahead of patients' and the public's health, and careful regulation that would decrease some of the more dangerous practices used.  Of course, much more resistance might be achieved if physicians used a little more common sense when dealing with people who are obviously trying to sell them on goods, services, or ideas.  A good proportion of the deceptive methods discussed above could be countered by remembering the usefulness of humility, skepticism, and a few simple aphorisms.   

Again, as we have written repeatedly, not only should all conflicts of interest be disclosed for the sake of honesty, but physicians and other health professionals ought to consider repudiating most of all of them, maybe at some personal expense, but in the interest of re-establishing their commitment to putting the patient, not their own self-interest, or the vested interests of others, first.  


1.  Sah S, Fugh-Berman A. Physicians under the influence: social psychology and industry marketing strategies.  J Law Med Ethics 2013; 14:  . Link here:

2. Poses RM, Bekes C, Copare F, Scott WE.  The answer to "what are my chances, doctor?"  depends on whom is asked: prognostic disagreement and inaccuracy for critically ill patients.  Crit Care Med 1989; 17: 827-833.  Link here.

3. Poses RM,  McClish DK, Bekes C, Scott WE, Morley JN. Ego bias, reverse ego bias, and physicians' prognostic judgments for critically ill patients. Crit Care Med 1991; 19: 1533-1539.  Link here.
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