A wrecked car idles on the side of the road; four bottles of wine and two handles of whisky are in the back seat—the driver, an adult male, is unconscious in the front seat. The police arrive and call the paramedics. The situation looks bleak.
What do you make of this story? It’s difficult to avoid jumping to the intuitive conclusion without first considering the number of sober drivers who drive with alcohol. Every year, many cars that contain alcohol get into accidents. How many are caused by the driver consuming that alcohol? How many involve sober drivers who just happened to have alcohol?
The mind processes information fast, often generating a clean casual chain with just a few variables—Car crash. Alcohol. Unconscious driver. Drunk driving. But if we want to understand what happens in the world we must consider information that is not immediately apparent. This, however, is difficult.
In 1967, two psychologists presented participants with the following numbers: 147, 724, 947, 421, 843, 394. What do they have in common? Four is in each of them. Now consider another list: 239, 639, 865, 795, 261, 756. What do these numbers have in common? Four is in none of them. “What can we learn from this?” asks Rolf Dobelli in his book The Art of Thinking Clearly. “Absence is much harder to detect than presence.”
An analogous problem occurs when we attempt to understand business performance. If, for example, the price of a stock decreases while the CEO was on vacation, it’s intuitive to connect the two and conclude that the stock decreased because the CEO was on vacation. But this is the stuff of headlines. We must remember all those vacationing CEOs whose companies managed just well without them, even if such news does not make the front page.
Epictetus - Enchiridion CXLII
Nature has given to men one tongue, but two ears, that we may hear from others twice as much as we speak.
La Rochfoucauld - Collected Maxims V:142
As great minds have the ability to say much in few words, so, conversely, small minds have the gift of talking much and not saying anything.
Attributed to Plato, but origins likely unknown
Wise men talk because they have something to say; fools, because they have to say something.
Plutarch - On Listening
Anyone who has acquired the ability to listen in a self-controlled and respectful fashion is receptive to and retentive of any remarks that are useful, while any that are useless or false are quite transparent to him and easily detectable, because he is–as is obvious–aiming at the truth rather than at winning an argument, and does not pitch in head first for a fight.
Regression to the mean: if the first measurement is extreme, the second is likely closer to the average. If the second measurement is extreme, the first is likely closer to the average. In the long run stocks, athletes, academics, the time it takes to fly from New York to Chicago, your immune system and your intelligence will hover around an average.
Consider the so-called SI Jinx. Cover-warranting performances are usually extraordinary, which means the athlete will regress back to his normal level of performance. Jordan was on the cover of SI so many times because his normal level was extraordinary. A coach yells at his team after a poor performance. The team plays well the next match. It appears that the coaches’ antics caused performance to improve, but the team simply regressed back to their normal level of play. You have a shitty week, go to your therapist, and the next week is normal. You would most likely have returned to normal without a visit to the therapist.
People say “I was sick, took a pill/went to the doctor, and got better” to suggest the pill/doctor visit caused improvement. This is almost always an incorrect inference, implying a causal relationship where no such thing exists. Minus bad injuries or extreme illness, the body heals itself perfectly fine without intervention. Since your immune system will normally regress back to its default state, do yourself a favor and do nothing if you experience a non-fatal illness. (no DayQuil).
Inaction is an optimal strategy much more than you think. Yet humans are plagued by a bias to do something to correct mistakes/errors/hardship when such things are commonplace events that your body and mind are perfectly prepared to handle.
Why were bleeding, vomiting and purging practiced for some 2,350 years? Doctors who performed these heinous operations were trying achieve something the body was also trying achieve: health. When bleeding, vomiting, and purging did not kill a patient they appeared to save the patient. This is a straightforward example of confusing a correlation with a cause. Ironically, the same problem still pervades medicine today: we intervene when intervention is unnecessary, and if the body self-heals we believe (mistakenly) that the intervention (and not the body’s normal recovery processes) helped. To make matters worse, we recommend the intervention to others–doctors prescribe it and big pharma mass produces it.
Three errors outlined by David Wootton in his very excellent book Bad Medicine:
1. We ignore non-events:
What we need in cases such as these is a history, not of progress, but of delay; not of events, but of non-events; not of inflexible logic but of a sloppy logic, not of overdetermination, but of underdetermination.
Because we have not listened out for the screams, we never hear the eerie silence that fell over operating tables in the 1850s.
Since this book argues that real medicine begins with germ theory, at its heart there is a most puzzling historical non-event: the long delay that took place between the discovery of germs and the triumph of germ theory.
2. Knowledge and therapy are together in hindsight, but separate in reality:
We tend to assume that where there is progress in knowledge there is progress in therapy… but before 1865 progress in knowledge rarely led to improvements in therapy.
Between the sixteenth and the nineteenth centuries, ideas about the body changed fundamentally, but therapies changed very little. Bloodletting was the main medical therapy in 1500, 1800, and 1850. The discovery of the circulation of the blood (1628), of oxygen (1775), of the role of haemoglobin (1862) made no difference; the discoveries were adapted to the therapy rather than vice versa.
Harvey announced that the heart pumped blood through the arteries in 1628; yet the use of the tourniquet in in amputations, which one would have thought was an absolutely elementary application of Harvey’s theory, was first pioneered by Jean Louis Petit (1674-1750), roughly a century later. Leeuwenhoek saw what we would now loosely call germs, or more accurately bacteria, through his microscope in 1677; yet in 1820 microscopes had no place in medical research, and in 1881 the conflict between germ theorists and their opponents was only just entering its final phase. Penicillin was first discovered not in 1941 but in 1872. And so on.
3. Status quo and confirmation errors plagued the progress of medicine:
To think about progress, you must first understand what stands in the way of progress–in this case, the surgeon’s pride in his work, his professional training, his expertise, his sense of who he is… the obstacle was the surgeon’s own image of themselves.
In the late 18th century, something strange occurred: a revolution in medicine that should have happened did not.
It started in 1772, when Joseph Priestley, an English theologian, philosopher and chemist, synthesized nitrous oxide. The compound followed two very different trajectories. Within the scientific community, a few researchers followed up on Priestley’s discovery. One, Humphry Davy, noted that nitrous oxide “appears capable of destroying physical pain” and recommended that “it may probably be used with advantage during surgical operations.” The British upper class had a different idea. The laugh-inducing compound became a popular recreational drug; laughing gas parties were commonplace. Yet for nearly half a century, Davy’s suggestion was ignored. Not one doctor—or any of those giggling British aristocrats—thought of using nitrous oxide to dull the pain elicited by surgery. Thousands suffered in vain.
That changed in 1845 when a dentist and surgeons from Boston connected the dots. On October 16th, 1846, a team of surgeons administered an anesthetic gas to remove a larger tumor from a woman. She experienced no pain, survived, and modern anesthetics were born. “Gentle, this is no humbug,” declared John C. Warren, a dentist at the Massachusetts General hospital.
It’s difficult to ignore near-misses in history. In his early teens, Blaise Pascal constructed the first mechanical calculator, ideal for a 17th century accountant, yet ignored for 250 years. Mendel’s famous pea experiments were overlooked for decades after his death. Sanctorius Sanctorius invented the thermometer in the 17th century, but it did not become a standard tool for clinicians until the mod 19th century. Davy saw the benefits of nitrous oxide, but doctors ignored him. Why?
To think about progress, you must first understand what stands in the way of progress.