Why Checklists Deceive You

The Art of Thinking Clearly - Rolf Dobelli 2014

Why Checklists Deceive You

Feature-Positive Effect

Two series of numbers: The first, series A, consists of: 724, 947, 421, 843, 394, 411, 054, 646. What do these numbers have in common? Don’t read on until you have an answer. It’s simpler than you think: The number 4 features in each of them. Now examine series B: 349, 851, 274, 905, 772, 032, 854, 113. What links these numbers? Do not read further until you’ve figured it out. Series B is more difficult, right? Answer: None use the number 6. What can you learn from this? Absence is much harder to detect than presence. In other words, we place greater emphasis on what is present than on what is absent.

Last week, while on a walk, it occurred to me that nothing hurt. It was an unexpected thought. I rarely experience pain anyway, but when I do, it is very present. But the absence of pain I rarely recognize. It was such a simple, obvious fact, it amazed me. For a moment, I was elated—until this little revelation slipped from my mind again.

At a classical recital, an orchestra performed Beethoven’s Ninth Symphony. A storm of enthusiasm gripped the concert hall. During the ode in the fourth movement, tears of joy could be seen here and there. How fortunate we are that this symphony exists, I thought. But is that really true? Would we be less happy without the work? Probably not. Had the symphony never been composed, no one would miss it. The director would receive no angry calls saying: “Please have this symphony written and performed immediately.” In short, what exists means a lot more than what is missing. Science calls this the feature-positive effect.

Prevention campaigns utilize this well. “Smoking causes lung cancer” is much more powerful than “Not smoking leads to a life free of lung cancer.” Auditors and other professionals who employ checklists are prone to the feature-positive effect: Outstanding tax declarations are immediately obvious because they feature on their lists. What does not appear, however, is more artistic fraud, such as the goings-on at Enron and with Bernie Madoff’s Ponzi scheme. Also absent are the undertakings of “rogue traders,” such as Nick Leeson and Jerome Kerviel, to whom Barings and Société Générale fell victim. Financial vagaries of this kind are not on any checklist. And they do not have to be illegal: A mortgage bank will be on the lookout for credit risk due to a drop in the debtor’s income because this appears on its list; however, it will overlook the devaluation of property, say, through the construction of an incineration plant in the vicinity.

Suppose you manufacture a dubious product, such as a salad dressing with a high level of cholesterol. What do you do? On the label, you promote the twenty different vitamins in the dressing and omit the cholesterol level. Consumers won’t notice its absence. And the positive, present features will make sure that they feel safe and informed.

In academia, we constantly encounter the feature-positive effect. The confirmation of hypotheses leads to publications, and in exceptional cases these are rewarded with Nobel Prizes. On the other hand, the falsification of a hypothesis is a lot harder to get published, and as far as I know, there has never been a Nobel Prize awarded for this. However, such falsification is as scientifically valuable as confirmation. Another consequence of the effect is that we are also much more open to positive advice (do X) than to negative suggestions (forget about Y)—no matter how useful the latter may be.

In conclusion: We have problems perceiving nonevents. We are blind to what does not exist. We realize if there is a war, but we do not appreciate the absence of war during peacetime. If we are healthy, we rarely think about being sick. Or, if we get off the plane in Cancún, we do not stop to notice that we did not crash. If we thought more frequently about absence, we might well be happier. But it is tough mental work. The greatest philosophical question is: Why does something and not nothing exist? Don’t expect a quick answer; rather, the question itself represents a useful instrument for combating the feature-positive effect.