Trust and Revenge Are Irrational—But Vital to Our Society

Big Think: What would the world be like if everyone always acted rationally?

Dan Ariely:  I think the world would actually be quite terrible if everybody would be perfectly rational.  And, you know, when you a ask people this question initially, you say, “Oh, yes, I want everybody to be rational.”  But the fact is, that I picked the title, "The Upside of Irrationality," because I think there’s a lot of wonderful things about irrationality.  I’ll give you two examples.

The first one is, imagine that you left your wallet on your desk and you went out for lunch.  What are the odds that somebody will steal it, right?  And now think about what are the odds that somebody would steal it if everybody you worked with was perfectly rational?  If everybody was constantly doing the cost benefit analysis, if that’s all what people were doing, they would pass by your desk, they would say, “Hey, nobody’s here, nobody’s looking, I can steal this and have no chance of being caught, let me do that,” right?  In fact, if we lived in a society where everybody was just maximizing their own self-interest all the time, it would be quite a terrible place to live. 

Here’s another example: Imagine a game we call the "trust game" and then I’ll tell you about the trust game with revenge.  So imagine two players, player A and player B.  And the trust game looks like this.  We tell player A, “Hey, player A, you have $20.  You can do two things, you can either go home or you can give your money to player B.  And you don’t know who player B is and you’ll never meet them.  If you sent your money to player B, player B will get $80, the money will quadruple magically on the way.  And now player B could decide to do two things, they could go home with $80, in which case you will get nothing, or they could send you back half the money.”  Now, think about this situation, imagine you’re player A and you’re asking yourself, “What would player B do?”  If player B was perfectly rational, what would they do?  They will go home with all the money, right?  They will maximize their self-interest. Why would they give you back any money?  So if you thought that player B was perfectly rational, would you send them the money?  Of course not, right?  So the rational prediction is that player B will never send the money back and because of that, player A will never trust him to start with.

Turns out people are much nicer than economic theory predicts.  There’s a good chance that player A will send the money and a good chance that player B will send half the money back and if you were player B, you can just imagine, imagine you just got in the mail somebody that says, "Hey, here's what happened, would you send the money back or not, right?"  Most people would do it.

So people... this is the case when people are nice in economic theory.  But imagine if you’re player A, and you send the money to player B, and player B took the money and left.  And now I come to you and I say, "Really sorry, player A, you lost all your money, but I tell you what?  If you go into your checking account and you get more money out and you give it to me, for every dollar you give me, I will go, I will hunt player B down and I’ll take $2 away from them.  You give me $2, I’ll hunt them down and take four.  You give me 10, I’ll hunt them down and take 20 from them."  And the question is, would you lose more of your own money to exert revenge on them?  You just lost $20 and you can lose even more to exert revenge on them.  And everybody who had a divorce or a big break up know the answer, right?  When we feel betrayed, we would spend lots and lots of money to inflict even more pain on the other side.  And when Ernst Fehr and some of his friends did work like this, they basically put people in an imaging so they could image people’s brains while they were executing and plotting revenge.  And what they saw was that the activity of revenge was rewarding, it was pleasurable.

Now, again, it’s irrational—why would it be rewarding and pleasurable?  Think about it this way, imagine that you and I were living on a desert island and imagine I had a mango and you wanted my mango, and imagine I kind of looked, I was away for a minute, and you could steal my mango.  If you thought that the only thing I was doing is a cost-benefit analysis, you would say, "Hey, if I steal Dan’s mango and run far away enough, he will do the cost-benefit analysis, he will decide not to chase me, not to find out what happened, he’ll just go and get a new mango.”  And under those circumstances, a good chance you’ll take my mango away.  But what if I was a revengeful type, what if you knew that if you stole my mango, I will not sleep and I will not rest.  I will hunt you down, it doesn’t matter how long it will take me and how far I’ll have to run and how many nights I will not sleep, I will hunt you down, I’ll take my mango and all your bananas and your goat and your whatever, whatever it is.  Under that condition, you will probably not start with me to start with, right?  You will not take anything away.

So the way to understand it is that trusting is irrational but we do it.  Revenge is irrational but we do it, and we do it because trust and revenge are actually two sides of the same coin.  Trust is incredibly important for society.  Imagine how we would live in a society without trust.  But to have trust, we also have to have revenge and those things together make sense.  They are both irrational, but they both make sense and they actually help us to live in a better society.  So would I prefer a society where everybody is rational—I don’t think so, not in a long shot.

Recorded on June 1, 2010
Interviewed by David Hirschman

The world would be a terrible place if everybody acted rationally all the time.

Scientists find a horrible new way cocaine can damage your brain

Swiss researchers identify new dangers of modern cocaine.

Getty Images
Mind & Brain
  • Cocaine cut with anti-worming adulterant levamisole may cause brain damage.
  • Levamisole can thin out the prefrontal cortex and affect cognitive skills.
  • Government health programs should encourage testing of cocaine for purity.
Keep reading Show less

Bespoke suicide pods now available for death in style

Sarco assisted suicide pods come in three different styles, and allow you to die quickly and painlessly. They're even quite beautiful to look at.

The Sarco assisted suicide pod
Technology & Innovation

Death: it happens to everyone (except, apparently, Keanu Reeves). But while the impoverished and lower-class people of the world die in the same ol' ways—cancer, heart disease, and so forth—the upper classes can choose hip and cool new ways to die. Now, there's an assisted-suicide pod so chic and so stylin' that peeps (young people still say peeps, right?) are calling it the "Tesla" of death... it's called... the Sarco! 

Keep reading Show less
Politics & Current Affairs

Political division is nothing new. Throughout American history there have been numerous flare ups in which the political arena was more than just tense but incideniary. In a letter addressed to William Hamilton in 1800, Thomas Jefferson once lamented about how an emotional fervor had swept over the populace in regards to a certain political issue at the time. It disturbed him greatly to see how these political issues seemed to seep into every area of life and even affect people's interpersonal relationships. At one point in the letter he states:

"I never considered a difference of opinion in politics, in religion, in philosophy, as cause for withdrawing from a friend."

Today, we Americans find ourselves in a similar situation, with our political environment even more splintered due to a number of factors. The advent of mass digital media, siloed identity-driven political groups, and a societal lack of understanding of basic discursive fundamentals all contribute to the problem.

Civil discourse has fallen to an all time low.

The question that the American populace needs to ask itself now is: how do we fix it?


Discursive fundamentals need to be taught to preserve free expression

In a 2017 Free Speech and Tolerance Survey by Cato, it was found that 71% of Americans believe that political correctness had silenced important discussions necessary to our society. Many have pointed to draconian university policies regarding political correctness as a contributing factor to this phenomenon.

It's a great irony that, colleges, once true bastions of free-speech, counterculture and progressiveness, have now devolved into reactionary tribal politics.

Many years ago, one could count on the fact that universities would be the first places where you could espouse and debate any controversial idea without consequence. The decline of staple subjects that deal with the wisdom of the ancients, historical reference points, and civic discourse could be to blame for this exaggerated partisanship boiling on campuses.

Young people seeking an education are given a disservice when fed biased ideology, even if such ideology is presented with the best of intentions. Politics are but one small sliver for society and the human condition at large. Universities would do well to instead teach the principles of healthy discourse and engagement across the ideological spectrum.

The fundamentals of logic, debate and the rich artistic heritage of western civilization need to be the central focus of an education. They help to create a well-rounded citizen that can deal with controversial political issues.

It has been found that in the abstract, college students generally support and endorse the first amendment, but there's a catch when it comes to actually practicing it. This was explored in a Gallup survey titled: Free Expression on Campus: What college students think about First amendment issues.

In their findings the authors state:

"The vast majority say free speech is important to democracy and favor an open learning environment that promotes the airing of a wide variety of ideas. However, the actions of some students in recent years — from milder actions such as claiming to be threatened by messages written in chalk promoting Trump's candidacy to the most extreme acts of engaging in violence to stop attempted speeches — raise issues of just how committed college students are to
upholding First Amendment ideals.

Most college students do not condone more aggressive actions to squelch speech, like violence and shouting down speakers, although there are some who do. However, students do support many policies or actions that place limits on speech, including free speech zones, speech codes and campus prohibitions on hate speech, suggesting that their commitment to free speech has limits. As one example, barely a majority think handing out literature on controversial issues is "always acceptable."

With this in mind, the problems seen on college campuses are also being seen on a whole through other pockets of society and regular everyday civic discourse. Look no further than the dreaded and cliche prospect of political discussion at Thanksgiving dinner.

Talking politics at Thanksgiving dinner

As a result of this increased tribalization of views, it's becoming increasingly more difficult to engage in polite conversation with people possessing opposing viewpoints. The authors of a recent Hidden Tribes study broke down the political "tribes" in which many find themselves in:

  • Progressive Activists: younger, highly engaged, secular, cosmopolitan, angry.
  • Traditional Liberals: older, retired, open to compromise, rational, cautious.
  • Passive Liberals: unhappy, insecure, distrustful, disillusioned.
  • Politically Disengaged: young, low income, distrustful, detached, patriotic, conspiratorial
  • Moderates: engaged, civic-minded, middle-of-the-road, pessimistic, Protestant.
  • Traditional Conservatives: religious, middle class, patriotic, moralistic.
  • Devoted Conservatives: white, retired, highly engaged, uncompromising,
    Patriotic.

Understanding these different viewpoints and the hidden tribes we may belong to will be essential in having conversations with those we disagree with. This might just come to a head when it's Thanksgiving and you have a mix of many different personalities, ages, and viewpoints.

It's interesting to note the authors found that:

"Tribe membership shows strong reliability in predicting views across different political topics."

You'll find that depending on what group you identify with, that nearly 100 percent of the time you'll believe in the same way the rest of your group constituents do.

Here are some statistics on differing viewpoints according to political party:

  • 51% of staunch liberals say it's "morally acceptable" to punch Nazis.
  • 53% of Republicans favor stripping U.S. citizenship from people who burn the American flag.
  • 51% of Democrats support a law that requires Americans use transgender people's preferred gender pronouns.
  • 65% of Republicans say NFL players should be fired if they refuse to stand for the anthem.
  • 58% of Democrats say employers should punish employees for offensive Facebook posts.
  • 47% of Republicans favor bans on building new mosques.

Understanding the fact that tribal membership indicates what you believe, can help you return to the fundamentals for proper political engagement

Here are some guidelines for civic discourse that might come in handy:

  • Avoid logical fallacies. Essentially at the core, a logical fallacy is anything that detracts from the debate and seeks to attack the person rather than the idea and stray from the topic at hand.
  • Practice inclusion and listen to who you're speaking to.
  • Have the idea that there is nothing out of bounds for inquiry or conversation once you get down to an even stronger or new perspective of whatever you were discussing.
  • Keep in mind the maxim of : Do not listen with the intent to reply. But with the intent to understand.
  • We're not trying to proselytize nor shout others down with our rhetoric, but come to understand one another again.
  • If we're tied too closely to some in-group we no longer become an individual but a clone of someone else's ideology.

Civic discourse in the divisive age

Debate and civic discourse is inherently messy. Add into the mix an ignorance of history, rabid politicization and debased political discourse, you can see that it will be very difficult in mending this discursive staple of a functional civilization.

There is still hope that this great divide can be mended, because it has to be. The Hidden Tribes authors at one point state:

"In the era of social media and partisan news outlets, America's differences have become
dangerously tribal, fueled by a culture of outrage and taking offense. For the combatants,
the other side can no longer be tolerated, and no price is too high to defeat them.
These tensions are poisoning personal relationships, consuming our politics and
putting our democracy in peril.


Once a country has become tribalized, debates about contested issues from
immigration and trade to economic management, climate change and national security,
become shaped by larger tribal identities. Policy debate gives way to tribal conflicts.
Polarization and tribalism are self-reinforcing and will likely continue to accelerate.
The work of rebuilding our fragmented society needs to start now. It extends from
re-connecting people across the lines of division in local communities all the way to
building a renewed sense of national identity: a bigger story of us."

We need to start teaching people how to approach subjects from less of an emotional or baseless educational bias or identity, especially in the event that the subject matter could be construed to be controversial or uncomfortable.

This will be the beginning of a new era of understanding, inclusion and the defeat of regressive philosophies that threaten the core of our nation and civilization.