It was a busy Friday night in the ER. A 34-year old woman came in with chest pain, and I saw her chest x-ray. I was just about to call it “normal” and move onto the next case, when a nagging little voice in the back of my head told me to look one more time. Can you see the abnormality? (Click on image to see it full sized):
I decided that I didn’t like a very subtle shadow in her right upper lung. It was just a little too asymmetrically dense compared to the opposite left side:
Hence, I told the ER doctor that there was a possible but not definite abnormality in that area (such as an early pneumonia). I recommended that he order a CT scan to see if it was real or not. He ordered the CT scan, and we saw this:
Based on the irregular contour (and other features), this is almost certainly a 2-cm lung cancer rather than pneumonia. The patient is now “in the system”, and we expect biopsy proof soon.
If I had decided to ignore that nagging doubt and instead called her x-ray normal, then 6 months later when the cancer had grown and become obvious, some sharp lawyer could easily have gone back through the records, reviewed the film, and argued that I should detected it back then.
Hence, I probably avoided a lawsuit by taking a second careful look at her x-ray, even though it was a crazy busy night in the ER with x-rays, CT scans, ultrasounds, and MRI images piling up.
Lesson: If a little nagging voice in your head tells you to look at or think about something one more time, then listen to it!
This is, of course, the thesis of Malcolm Gladwell’s book Blink. And I believe Gladwell is fundamentally correct.
If one has trained one’s subconscious to make good “lightning” evaluations over the years through a process of reason (in adherence to the facts of reality), then one’s resultant “intuitions” can be quite valuable. At the very least, one should take those intuitions seriously — in the sense of using them as a red flag indicating that one should reconsider the issue at hand and apply some more careful conscious reasoning.
Of course, if one’s “intuitions” are just a hodgepodge of emotional reactions shaped by chance and whim, then they will almost certainly lead one astray. And Gladwell also emphasizes this point in his book.
Dr. Leonard Peikoff also covers this topic nicely in his Podcast #103 (timestamp 6:55), answering the question on intuition.