What is the Ultimatum game? (2023)

You're standing on the sidewalk with a friend minding your own business when aMannapproaches with a suggestion. He offers you $20 in one dollar bills and says you can keep the money with one condition: you must share some of it with your friend. You can offer your friend as much or as little as you like, but if your friend declines your offer, neither of you may keep any of itMoney. How are you?

This isn't the premise for a spin-off of the TV show Cash Cab; rather it is aBusinessExperiment that offers some interesting insights into the human psyche. It's called theUltimatives Spiel.


Now you have the $20 in your hand and your friend is looking at you expectantly. Will you ball down your friend? Will you split the money evenly? will you be generous

From a purely utilitarian perspective on economics, you would give your friend the least amount possible. In this case, you have $20 bills, so you would give your friend a dollar. Since this is found money, your friend should accept the dollar. Your friend might call you cheap, or might offer you a bit of gratitude to be liberally showered onsarcasm-- but, hey, at least he or she made a dollar out of it.

The thing is, this strictly utilitarian view doesn't carry over to how people actually behave when faced with that choice. In experiments based on the ultimatum game, test subjects on the receiving side regularly reject offers that they find too low. And in others, subjects who must decide how much to give often bid more than the lowest amount.

This unlikely behavior offers a unique insight into the human mind and how we function as social animals. Find out on the next page how we behave during the game – and what happens when the tables are turned.

(Video) The Ultimatum Game | The Greatest Example of Human "Irrationality"

Video Gallery: Cold Hard Money

The Ultimatum game is all about money. Learn more about money basics in these HowStuffWorks videos:

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  1. How the ultimatum game works
  2. Evolution and the Ultimatum game

How the ultimatum game works

What is the Ultimatum game? (2)

The ultimatum game is the brainchild of Israeli game theorist Ariel Rubinstein, who predicted in 1982 that a person asked for a decision in such a game would choose to bid the lowest possible amount. This term describes a behavior calledrational maximization-- the tendency to choose more for oneself.

The following year, Rubinstein's prediction was tested by three economists - Werner Güth, Rolf Schmittberger and Bernd Schwarze. The three researchers found results in their test of the ultimatum game that directly contradicted Rubinstein's predictions — the average offer from one participant to the other was about 37 percent of the money. Other studies found an average offer between 40 and 50 percent. Even more so, about half of recipients declined offers below 30 percent [source:Indiana University].


The researchers' findings opened a floodgate for speculation and further research. Why do people behave so unreasonably? One answer was fear of rejection. If a giver knows that his or her offer can be rejected, and that refusal could cost him or her the rest of the money, the giver might be more inclined to make a fair offer. This theory is undermined by another study using a variation of the ultimatum game, thedictator game.

In this version, the giver keeps the money regardless of whether the receiver declines the offer. A 1986 experiment gave subjects two choices: the giver could either split the $20 evenly, or offer the receiver $2 and keep $18. In either case, the giver must keep the money regardless of whether the recipient accepts or rejects the offer. Seventy-six percent of givers chose to split the money evenly, despite knowing beforehand that the recipient would have to take whatever the giver gave [source:Indiana University].

Other studies come to different conclusions. A variant of the dictator game released in 2002 created a test where the receiver in one round would be the dictator in the next round. They found that what the former recipient-turned-dictator received in the second round "correlated strongly with the amount received in the first round" [source:Ben-Ner, et al.]. In other words, if a small amount was given to the recipient, he or she would leave it as the dictator of the person who short-circuited him or her.

What's going on here? Why wouldn't people rationally maximize across the board in ultimatum or dictator games? While fear of rejection is certainly a reasonable explanation for a giver's behavior, it does not explain why a recipient would ever turn down an offer or why someone would give more than is necessary. In this case, however, our concept of fairness would suffice as an explanation. Studies with primates have shed light on the influence of fairness and rational maximization in the ultimatum game. Learn more on the next page.


(Video) The Ultimatum Game- Are people rational?
(Video) The Ultimatum Game | The Science of Empathy

Evolution and the Ultimatum game

What is the Ultimatum game? (3)

It is possible that we humans have a sense ofaltruism, the desire to put the interests of others ahead of our own. Those who subscribeevolutionaryTheory states that such a mechanism should not exist; Some psychologists believe it is evidence of a higher mind that humans possess. This second theory is supported by the results of a 2007 study by the Max Planck Institute.

In the study, the chimpanzees were offered a variety of bowls of raisins in sets. Just like in the human version of the Ultimatum game, the voter could keep one but had to give up the second. The sets of raisins were divided differently. Some were fairer than others, and in some cases one chimpanzee of the pair received no raisins at all. The researchers found that the chimpanzees didn't care about the concept of fairness and accepted any offer that included raisins, no matter how evenly divided. The only time a chimpanzee declined an offer was in a case where no raisins were offered to the recipient [source:Max-Planck-Institut].


But this study doesn't rule out the possibility that we have a sense of fairness, especially when we're being treated unfairly. Additionally, a sense of fairness may not be unique to humans.

This is proven by a study from 2003. Researchers at Emory University in Atlanta conducted a study with capuchin monkeys. The subjects in the study, all women, were taught to trade pebbles for a slice of cucumber. Upon learning that diatomaceous cucumbers were synonymous, the monkeys were mated. At first the trades were fair. But as the research progressed, the monkeys saw their partners receive a grape from the researchers in exchange for pebbles, while others continued to receive cucumbers. To make matters worse, some monkeys were given grapes or cucumbers for doing nothing while their partners had to fetch a pebble and bring it to the researcher. As the unfair trade continued, the losing partners became angry [source: Emory University].

(Video) Game Theory 101: The Ultimatum Game

None of these studies touch on another aspect found in studies of the ultimatum game - not the lack of fairness, as in the capuchin study, but the presence of fairness. Why would anyone give more than they had to as discovered in The Dictator Game? A 2001 study concluded that people who engaged in negotiation games such as the ultimatum game actively seek out and display nonverbal cues during the negotiation phase. We humans, the researchers theorize, are simply good at judging others and how they will react to a low offer in the case of the ultimatum game [Eckel and Wilson].

The ability to infer how another person will react when they have fallen short, along with having a sense of fairness, would certainly explain the results found in studies of the ultimatum game. Of course, you could say it's a pretty onedepressingexplanation, but.

For more information on evolution and the human brain and other related topics, see the next page.


Lots more information

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More great links

  • Ben-Ner, et al. "Reciprocity in a two-part dictator game." University of Minnesota. March 2002. http://www.legacy-irc.csom.umn.edu/RePEC/hrr/papers/0902.pdf
  • Eckel, Catherine and Wilson, Rick K. "Why Fairness?: Facial Expressions, Evolutionary Psychology, and the Emergence of Fairness in Simple Negotiation Games." Virginia Polytechnic Institute and State University and Rice University. May 1, 2001. http://www.ruf.rice.edu/~rkw/RKW_FOLDER/Harvard_RKW.pdf
  • McCabe, Kevin. "What is the Ultimatum Game?" neuroeconomics. September 24, 2003. http://neuroeconomics.typepad.com/neuroeconomics/2003/09/what_is_the_ult.html
  • McMillan, Susan. "Monkeys have a sense of fairness." November 19, 2007. Emory Wheel. http://www.emorywheel.com/detail.php?n=24747
  • Rotemberg, Julio J. "Minimal Acceptable Altruism and the Ultimatum Game." Federal Reserve Bank of Boston. 23 May 2006. http://www.bos.frb.org/economic/wp/wp2006/wp0612.pdf
  • Uchitelle, Louis. "Economist honored for use of psychology." New York Times. 28 April 2001. http://query.nytimes.com/gst/fullpage.html?res=9D0DE4D71039F93BA15757C0A9679C8B63
  • "Chimpanzees, unlike humans, apply economic principles to ultimatum game." Max Planck Institute. October 5, 2007. http://www.sciencedaily.com/releases/2007/10/071005104104.htm
  • "Money is not everything." The economist. 5 July 2007. http://www.economist.com/science/displaystory.cfm?story_id=9433782
  • "Ultimatum Game." Indiana University. ch.indiana.edu/rgoldsto/complex/ultimatum.ppt+ultimatum+game&hl=en &ct=clnk&cd=6&gl=us
(Video) The Ultimatum Game


What is the explanation of ultimatum game? ›

The Ultimatum Game is a paradigmatic two-player game. A proposer can offer a certain fraction of some valuable good. A responder can accept the offer or reject it, implying that the two players receive nothing. The only subgame-perfect Nash equilibrium is to only offer an infinitesimal amount and to accept this.

What is the ultimatum game example? ›

A canonical example is the Ultimatum Game: one player proposes a division of a sum of money between herself and a second player, who either accepts or rejects. Based on rational self-interest, responders should accept any nonzero offer and proposers should offer the smallest possible amount.

What is the conclusion of the ultimatum? ›

In the end, Randall proposed to Shanique, and she accepted. THE REUNION: After the show, Shanique and Randall ended their engagement and remained broken up for six months. During that time, Shanique went on a few dates while Randall stayed single after losing multiple people close to him.

What are the rules of the ultimatum? ›

Each contestant had to stand up, with the rest of the cast watching, and say who they wanted to live with. The selected person then has to stand up and say if they want to choose the person who's picked them. However, if the feelings aren't mutual, contestants can choose someone else instead.

What is an example of a strategy game? ›

Examples of this genre are the Civilization, Heroes of Might and Magic, Making History, Advance Wars and Master of Orion. TBS games come in two flavors, differentiated by whether players make their plays simultaneously or take turns.

What is the difference between the dictator game and the ultimatum game? ›

Mean offers in the Dictator Game are about 20% of the initial amount (Oxoby and Spraggon, 2008), and mean offers in the Ultimatum Game are usually between 30 and 40% of the initial amount, with the most common offer being a 50–50 split (Camerer and Thaler, 1995).

What is the ultimatum game 100 dollars? ›

The Ultimatum Game is a simple game in which two players attempts to split a $100 reward. They can communicate with each other for 10 minutes, after which: Player 1 proposes an integer split (e.g. $75 for Player 1, $25 for Player 2) Player 2 may Accept or Reject this split.


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