Wikipedia Commons / Public Domain
Source: Wikipedia Commons / Public Domain

In 2011, Dan Sperber and Hugo Mercier, two French social cognitive scientists, published a paper that stirred the scientific world, fundamentally altering the way leaders should solve problems and make decisions. Reasoning, they concluded in their controversial paper, has an argumentative function. That conclusion, however hum-drum and technical sounding it may be, doesn’t quite do justice to how profoundly consequential it is. So let me try another way:

Imagine, for a moment, that you’re a sawyer living in a remote forest. While taking a stroll one day, you see a long beautiful saw lying there on the ground. After a quick glance in both directions, you pick it up and with little hesitation, get to work.

The saw does a pretty good job slicing through the lumber but as you soon realize, it’s not without its problems. Aside from the fact that the thing is big and unwieldy, the damn teeth keep getting caught in the push stroke, forcing you to stop every few moments to readjust. But, good enough, you think. The saw becomes your trusted tool for many years and once other sawers catch wind, they copy the design and the saw spreads throughout the entire community.

One day though, two strange men dressed in white lab coats carrying clipboards come to your home armed with a stunning revelation: you and your compatriots have been using the tool all wrong.

The two men pick up the saw and point out something you’ve never quite seemed to notice: both ends have handles. The reason why the saw is so large and keeps getting caught, they inform you, is that it was never intended for one person. It's a two-person saw.

Well now, imagine those two clipboard-carrying men are Sperber and Mercier. And that saw isn’t really a saw, it’s your brain.

Thinking—something we’ve done our entire lives to help us solve problems and make better decisions—was never designed for solitary use, claim Sperber and Mercier. It was designed to do with a partner.

The Problem with Thinking Alone

Envision a great thinker trying to solve a difficult problem and what do you see? Perhaps an image of an old monk meditating on a mountaintop, or a woman writing formulas on a chalkboard, papers strewn all over the floor of her office, or maybe a philosopher in the wilderness, sitting on a stone like Rodin’s The Thinker, fist pressed against chin, deep in contemplation. Whatever the image, let me ask you, is the thinker alone?

Embedded in our minds is a presumption, one that we’ve probably never thought to question, that thinking, at its heart, is a solitary activity. To clarify, when I use the term thinking, I’m referring to a particular kind: reasoning — the slow and effortful kind of thinking whereby we mentally contemplate and decide what to believe and what not to believe. And our presumption is, it’s not that we can’t perform this kind of thinking with other people, it’s just not it’s natural form.

But if lone thinking is in fact so natural, we ought to ask a simple question: are we any good at it? Surprisingly enough, according to Sperber and Mercier, the answer is no.

A large body of experimental evidence has proven humans depressingly inept at lone thinking exercises. Take for example the Wason Selection Task, a logical deduction exercise, administered thousands of times over the past two decades. In laboratory experiments, subjects fail this elementary reasoning task at astonishing rates, generally only 10 percent getting it right.

One reason for the dismal results is the confirmation bias: the psychological phenomenon where humans seek out and treat more favorably information that confirms what we already believe (or simply want to believe).

To see how the confirmation bias leads lone thinkers astray, just imagine making a pros and cons list for a decision that you’re already pretty excited about making.

Say you’re dying to buy an absurdly expensive sports car (that the sane part of you knows you don’t need). Watch how effortlessly you generate a long list of pros—the leather seats, the horsepower, the heads you’ll turn on the highway—but strain to come up with nearly as many cons.

It’s not that there aren’t as many—the price, the cost of maintenance, the hell your spouse will give you when they inevitably find out—it’s just that the confirmation bias makes them difficult to see. And this sort of asymmetrical analysis is guaranteed to lead to some very bad decisions.

But a question that has dogged psychologists since it’s discovery is this: why in the world would the confirmation bias, if it’s such an Achilles’ heel, survive so many years of evolution?

Enter Sperber and Mercier who suggest that maybe the bias only looks like a weakness because we’ve always assumed, wrongly, that thinking was designed for an individual. When two people think together, they point out, it’s revealed as a tremendous strength.

The Power of Thinking Together

In order to understand why two-person thinking is so powerful, we need to revisit our sawyer metaphor for a moment.

Sawing, as even a casual observer will notice, requires both a pushing and pulling motion. But these two movements are seldom equal. Ergonomically, many sawers find it easier to generate power when they pull compared to when they push. And having 50 percent of your activity be less efficient is a weakness, of course, unless you have a partner.

When both of you, facing each other, holding opposite ends of the saw, you each have the luxury of focusing exclusively on the motion for which you naturally favor, pulling. This beautiful division of labor turns the pull bias from a weakness into a strength.

Similarly, when two people think together, two people with divergent points of view that is, each person, instead of wasting his or her energy trying to come up with both pros and cons — can specialize in one, the one that their confirmation bias already has them favor. Sperber and Mercier call this a division of cognitive labor and it leads to more efficient thinking.

Back to the sports car. Remember that your pro-car bias made you better at generating reasons to buy the car, but less so at coming up with reasons to pass. But what if you were to work together with someone with an anti-car bias, someone like your spouse who, I can only assume is horrified by the potential purchase and is undoubtedly going to be better at coming up with cons.

When you both specialize (you on the pros, your spouse on the cons), you’re able to produce a more comprehensive pros-and-cons list. This process of specialized thinking with others has a name: arguing. And it’s the key to making better decisions.

Study after study shows that in argumentative settings, when people think together, they outperform individuals. One stunning example that Sperber and Mercier highlight is the Wason task that we talked about earlier. Recall that individuals get the task right only 10 percent of the time, but when groups take the test, that number skyrockets to 80 percent.

Granted, thinking together is not a new idea. Who amongst us hasn’t reached out to a friend or colleague to talk through a decision we’re struggling to make? But realistically, how often? And more importantly, when we do, are we approaching people who are actually willing to disagree with us?

Whether we realize it or not, most people don’t feel empowered to be brutally honest. Either because they wish to avoid conflict, spare our feelings, or prevent potential personal or professional repercussions.

If we want to tap into the awesome power that arguing with others provides, however, we need to find those rare individuals who will be honest, who are willing and able to engage with us in intellectual combat.

As it turns out, history’s greatest minds have seemed to understand the inherent indispensability of these kinds of relationships. That’s why so many have had thinking partners.

Warren Buffet’s Thinking Partner

At an Omaha dinner party in 1959, Warren Buffett bumped into an old acquaintance, a humble yet opinionated lawyer named Charlie Munger. The two hit it off immediately. Buffet enjoyed Munger’s sense of humor, but it was Charlie’s refreshing candor that would eventually make him such an effective Vice Chairman at their investment firm, Berkshire Hathaway.

”Charlie says everything I do is dumb,” Buffet says, in the most appreciative way possible. The two would go on to debate and discuss all major decisions affecting the firm.

Early in his career, Buffett was keen on a buy-low-sell-high strategy, something he had learned from his former professor at Columbia University, Ben Graham. Although Buffett had some success with the approach, Charlie challenged him to reconsider: “You know, let's give this up, and really buy into some fine businesses.”

So Buffett switched to a more patient buy-and-hold investment strategy, paying far less attention to what the market was doing on a day to day basis, instead focusing on a company’s long-term underlying fundamentals. The pivot made Buffett the second richest person in the world, and he isn’t shy about giving the lion’s share of the credit to his trusted thinking partner, Charlie Munger.

Michael Crichton

The acclaimed author Michael Crichton had several thinking partners throughout his career: his editors. One day he got a call from famed literary editor Robert Gottlieb about a manuscript for a novel he just delivered. Gottlieb, always brutally honest, told Crichton there was something wrong with the final scene. It was backward.

In Crichton’s suspenseful climactic ending, one of the characters, in order to save the day, was supposed to turn on the switch to a nuclear device. Gottlieb though, pointed out something that Crichton hadn’t thought of: “No, no, the switch has to turn itself on automatically, and the character has to turn it off.”

“He was absolutely right,” Crichton admits.

And while Crichton doesn’t always relish in the conversations with his thinking partner, he knows they’re indispensable for his art. “I think every writer should have tattooed backward on his forehead, like ‘ambulance’ on ambulances, the words ‘everybody needs an editor’.”

Albert Einstein

Even Albert Einstein, a man who spent so much of his life lost in thought, had a thinking partner to bat around ideas with, his longtime friend Michelle Besso. Einstein called him the best sounding board in all of Europe.

And so, in 1902, when Albert Einstein had a problem that was baffling him. He showed up to Besso’s home and proclaimed, “I have come here to battle against this problem with you.” The two debated the matter for hours. When it was over, Einstein said, “Thank you.” and left. Five days later, Einstein showed up once again to Besso’s residence, this time announcing “I have the answer.” In just over a month the special theory of relativity was born.

The greatest minds have used thinking partners to their advantage, to help them solve hard problems, and make important decisions. But making these relationships work isn’t as easy as it looks. It requires two qualities that most people lack.

The Attitude Required to Have A Thinking Partner: Humility and Guts

Those who successfully recruit and work with thinking partners face the humble realization that no matter how intelligent they are, they simply don’t have all the answers and never will. Instead, they appreciate that all human beings are vulnerable to thinking errors, ones that they themselves are not in a good position to identify. After all, as the saying goes, you can’t read the label of the jar you’re stuck inside. That’s why they humbly give someone else permission to point those errors out to them.

But most importantly, those who are able to most effectively reap the benefits of their thinking partners have the guts necessary to give up even their most cherished ideas. This can be admittedly difficult, because of how easily we fall in love with them. Our ideas can come to feel like our own children, our darlings. And how dare others ask us to leave our darlings behind, we’re apt to think.

But that’s why we have to follow the timeless advice often given to young writers: kill your darlings. After all, what good is a thinking partner, if we’re not willing to be persuaded by them?


If Hugo Mercier and Dan Sperber’s argumentative theory of reasoning is correct, anyone interested in making good decisions and solving problems would be wise to spend a little less time thinking alone, and considerably more time arguing with others. Specifically, we should find those rare individuals who are willing to challenge us and recruit them as thinking partners.

But more generally, this fundamentally changes how we should think about thinking. The next time we envision a great thinker, instead of imagining them, in isolation, deep in thought, we should imagine them at a table side by side with a partner, exchanging ideas, listening intently, persuading and being persuaded.

Interested in putting these ideas into action? This 20-minute recorded webinar, led by Al Pittampalli, will show you how, specifically, to argue with your thinking partner, a framework called The Courtroom Method. 

Click here to sign up for the free recording >>

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