Those Wielding Hammers See Only Nails

The Art of Thinking Clearly - Rolf Dobelli 2014

Those Wielding Hammers See Only Nails

Déformation Professionnelle

A man takes out a loan, starts a company, and goes bankrupt shortly afterward. He falls into a depression and commits suicide.

None of them. “If your only tool is a hammer, all your problems will be nails,” said Mark Twain—a quote that sums up the déformation professionnelle perfectly. Charlie Munger, Warren Buffett’s business partner, named the effect the “man with the hammer tendency” after Twain: “But that’s a perfectly disastrous way to think and a perfectly disastrous way to operate in the world. So you’ve got to have multiple models. And the models have to come from multiple disciplines—because all the wisdom of the world is not to be found in one little academic department.”

Here are a few examples of déformation professionnelle: Surgeons want to solve almost every medical problem with a scalpel, even if their patients could be treated with less invasive methods. Armies think of military solutions first. Engineers, structural. Trend gurus see trends in everything (incidentally, this is one of the most idiotic ways to view the world). In short: If you ask people the crux of a particular problem, they usually link it to their own areas of expertise.

So what’s wrong with that? It’s good if, say, a tailor sticks to what he knows. The déformation professionnelle becomes hazardous when people apply their specialized processes in areas where they don’t belong. Surely you’ve come across some of these: Teachers who scold their friends like students. New mothers who begin to treat their husbands like children. Or consider the omnipresent Excel spreadsheet that is featured on every computer: We use them even when it makes no sense—for example, when generating ten-year financial projections for start-ups or when comparing potential lovers that we have “sourced” from dating sites. Excel spreadsheets might as well be one of the most dangerous recent inventions.

Even in his own jurisdiction, the man with the hammer tends to overuse it. Literary reviewers are trained to detect authors’ references, symbols, and hidden messages. As a novelist, I realize that literary reviewers conjure up such devices where there are none. T his is not a million miles away from what business journalists do, too. They scour the most trivial utterings of central bank governors and somehow discover hints of fiscal policy change by parsing their words.

In conclusion: If you take your problem to an expert, don’t expect the overall best solution. Expect an approach that can be solved with the expert’s tool kit. The brain is not a central computer. Rather, it is a Swiss Army knife with many specialized tools. Unfortunately, our “pocketknives” are incomplete. Given our life experiences and our professional expertise, we already possess a few blades. But to better equip ourselves, we must try to add two or three additional tools to our repertoire—mental models that are far afield from our areas of expertise. For example, over the past few years, I have begun to take a biological view of the world and have won a new understanding of complex systems. Locate your shortcomings and find suitable knowledge and methodologies to balance them. It takes about a year to internalize the most important ideas of a new field, and it’s worth it: Your pocketknife will be bigger and more versatile, and your thoughts sharper.