As a surgeon, I find Ben Carson particularly troubling. By pretty most reports, he was a skilled neurosurgeon who practiced for three decades, rising to the chief of neurosurgery at Johns Hopkins. Yet, when he ventures out of the field of neurosurgery—even out of his own medical specialty—he routinely lays down some of the dumbest howlers I've ever heard. For example, he denies evolution, but, even worse, he's been a shill for a dubious supplement company, Mannatech. Worse still, when called out for his relationship with Mannatech in the last Republican debate, Carson lied through his teeth about it. The pseudoscientific views he relates have been so bad that he led me to resurrect some old schtick that I had abandoned years ago about physicians denying evolution leading me to put a paper bag over my head in shame for my profession. I'm also reminded of it not just by media stories about Carson's latest verbal gaffe but because I work within easy walking distance of the Ben Carson High School of Medicine and Science, a STEM-related high school designed to encourage high school students to pursue careers in the sciences.

Most recently, video of a commencement speech he gave in 1998 was unearthed, and in it Carson contradicted the consensus among historians that the Egyptian pyramids were built as tombs for pharaohs and stated that he believed that they were, in fact, built by Joseph to store grain. (On the plus side, at least he said he didn't believe that aliens had anything to do with their construction.) His reasoning was—shall we say?—not convincing.

As a physician and a surgeon, I never cease to be amazed at how brilliant physicians, who are so knowledgeable and skilled at medicine, can be so irredeemably ignorant about topics not related to medicine, and even, as was the case with Ben Carson's dubious cancer cure testimonial for Mannatech, medical topics not related to their specific specialty. Indeed, Andy Borowitz nailed it well when portrayed Carson as "shattering the stereotype about brain surgeons being smart."

Or did he?

I was prodded to revisit this topic in a more general fashion first by Ben Carson's latest bomb of uncritical thinking (which shows that he's been the way he is for a long time, as the speech was from 1998), but also because Steve Novella brought it up as well. (It also helps that my last two posts have gotten crazy traffic for some reason, and I need, as Mr. Creosote was offered, a little wafer to cleanse the palate.) As much as I respect Steve, who, as usual, makes some most excellent points, as he asked (and tried to answer) the question, "How can one person be undeniably brilliant in one sphere of their intellectual life, and shockingly ignorant and anti-intellectual in other spheres?" regular followers of this blog know that there's always more that I can add when the mood takes me.

Before I begin, let me just say that I'm aware that, because of Carson's reputation as a brilliant neurosurgeon, certain activists on the left have been trying to discredit that reputation by dredging up malpractice cases that Carson has been involved in over the years. I've described these articles on Facebook as a cheap shot and intellectually dishonest, because they are. They examine Carson's record and compare it to physicians in general. Yet, according to a recent New England Journal of Medicine study, the most sued specialty is neurosurgery, with 19% of neurosurgeons per year being involved with at least one malpractice suit and roughly 99% of neurosurgeons being sued at least once before they retire. Comparing Carson's record to the record of the average doctor is a purposely deceptive comparison of apples and oranges. Carson's record should be compared to the records of neurosurgeons practicing in urban areas and doing high risk surgery of the sort that Carson did. Also the article only tells one side of the story, the plaintiffs', taking advantage of the fact that the hospital and Carson can't comment because of patient privacy concerns.

End of diversion.

Let's get back to the question of how someone as brilliant as Carson, who went to Yale University and attended medical school at the University of Michigan Medical School, followed by a neurosurgery residency at Johns Hopkins, can be so dense about so many things.

Steve is correct that Carson's brilliance as a neurosurgeon is not a contradiction, that we all share cognitive blindspots like his. All of us believe things without evidence, things that we find hard to let go of, even in the face of disconfirming evidence. This is undeniably true. I wouldn't, however, agree that Carson is a "perfect representation of humanity," for the simple reason that I think he represents an outlier, someone way on the end of the bell-shaped curve if you will. Most people don't hold dogmatically to so many bad ideas, or at least assert so many demonstrably incorrect ideas. Those who do tend to fall prey to crankery, like antivaccine activists, creationists, quacks, anti-GMO activists, and anthropogenic global climate change denialists. Carson clearly falls into this category, but why?

There appear to be two reasons, which Carson seems to exhibit in abundance. First, of course, is the Dunning-Kruger effect. This is a phenomenon in which humans with low expertise in a subject tend to overestimate their expertise in the subject and exhibit undue confidence in that expertise, which tends to be in marked contrast to real experts, who tend to underestimate their expertise on the subject and acknowledge a lot more uncertainty because, well, they know the limits of their knowledge. Physicians tend to be very prone to the Dunning-Kruger effect, for many reasons. Think about it. Medical school is very difficult to get into; so most doctors were excellent students all their lives before they became doctors. Once they get into medical school, they are not infrequently told how they are the "best of the best" and how they represent the future of medicine. I share one trait in common with Dr. Carson, and that's that I, too, graduated from the University of Michigan Medical School, and I still remember being told that on day one. I'd say that in some ways it's getting even worse. There was no such thing as a "white coat ceremony" at my medical school when I started, but these days most medical schools have a ceremony where the new class of students don their white coats as a symbol of the profession they are about to enter. I've never liked white coat ceremonies. Add to that residency, which, even after the 80 hour work week restrictions, is still like boot camp, designed to emphasize that we are tough enough to be physicians, and the sense that we are somehow "better" than the rest of society is reinforced.

Another issue is the privilege of physicians. Medical students might be at the bottom rung of the totem pole in the hospital, but they are told that they will soon be top dogs. And so they become top dogs. It's true that medical practice has become more collaborative over my time practicing surgery. Doctors are no longer the unquestioned kings (and queens) of the roost. However, they still hold enormous power and privilege in the hospital. That's not even counting the privilege that we as physicians are granted to probe the deepest secrets of our patients, administer medicine, and even, as surgeons do, forcibly rearrange people's anatomy for therapeutic intent. We get to see the innermost recesses of our patients' bodies. It's an incredible privilege that society has granted us. That privilege is reinforced by our being consulted not just for our expertise but by the assumption held by many that because we are experts in medicine we must be experts in a lot of other things too.

It's not surprising, then, that physicians might come to overestimate their ability to master another discipline, at least well enough to pontificate confidently on it. Of course we can! We're doctors! We made it through the ringer that is medical school, residency, and board certification. Just give me enough time and enough Google and we can learn anything! Is it any wonder that physicians are particularly prone to the Dunning-Kruger effect? Not to me, at least not any more. The same seems to be true of many other high-achieving people. There's a reason that most leaders in the antivaccine movement tend to be affluent, highly educated people. J.B. Handley, for instance, is a successful businessman who has basically said that he doesn't need to listen to us pointy-headed scientists and physicians; he's learned what he needs to learn about vaccines causing autism himself.

It's also correct that holding conspiracy beliefs and believing in pseudoscience do not mean that a person is stupid. Most people who hold such beliefs are not. In fact, thanks to the phenomenon of motivated reasoning, in which attacks on people's beliefs result in their clinging to them more tightly and where facts and evidence are used not to find the truth but to protect pre-existing views, it is often very intelligent people who are the most vocal proponents of pseudoscience. Their intelligence gives them a more potent skill set to protect their pre-existing beliefs against refutation than possessed by people of average or lower intelligence. Indeed, many of the people most invested in "integrating" alternative medicine (i.e., quackery) into medicine are incredibly intelligent physicians.

Every human being on the planet has the potential to believe the same nonsense that Ben Carson believes, and, make no mistake, his mass of pseudoscientific and conspiracy theory beliefs is enormous. In addition to his belief in Mannatech quackery, Carson believes that Barack Obama is part of a Communist conspiracy to bring down America, that gay rights is a Communist plot, and, of course, that the theory of evolution comes from Satan. Skepticism begins with recognizing this and having the humility to recognize that we all believe things without evidence. That's part of being human. Fortunately, once we recognize this, we can begin to test our beliefs against evidence and science and determine which ones are supported and which ones aren't. Most importantly, this testing must involve seeking out disconfirming evidence; otherwise we risk devolving into motivated reasoning, cherry picking evidence that supports our beliefs and discounting evidence that does not. We must be willing to change our minds when the evidence does not support our beliefs. It's a continuous, lifelong process.

Indeed, what disturbs me the most about Ben Carson is not that he holds these beliefs, although that certainly does disturb me. It's that he doesn't show any evidence of being willing to examine his own beliefs critically. He dismisses expert opinions and, when questioned, doubles down on previous inane statements. The only time he seems to change his mind is to pander, as he did when he reversed his support for school vaccine mandates at the first Republican debate. None of these are characteristics I want in my next President, regardless of politics. I've often quoted Dirty Harry that "a man's got to know his limitations." Think of skepticism as a tool to help us know our limitations with respect to knowledge and science.