Two teams play the ultimatum game. On the left- team human. On the right, team Chimpanzee. The game- a contest to find out which of the great apes is more rational. Chimp vs Man, head to head in an interspecies battle of intelligence.
The ultimatum game is a classic economic experiment. Normally, there are two players. One player is given 10 coins. He or she gets to chose how to divide them. The second player decides whether to accept how the coins are divided, or reject the offer. If the second player rejects the offer, nobody gets the coins.
For example, if player one offers a 5/5 split, player two will accept.
If player one offers a 6/4 split, player two will accept.
Now, if player one offers a 7/3 split, player two has doubts and thinks about rejecting.
If player one offers a 8/2 or a 9/1 split, player two will reject.
This anger at someone getting more than us and the spite we feel is very human, but it isn’t rational. If we were rational utility maximizers, we shouldn’t care what the other person gets. Player 2 should accept any deal because they are all better than the alternative- getting nothing.
On the other side of the room is team chimpanzee. They play with food, not with money.
If chimp one offers a 5/5 split, Chimp two will accept.
If Chimp one offers a 6/4 split, Chimp two will accept.
If Chimp one offers a 7/3 split, Chimp two will accept.
If Chimp one offers a 8/2 split, Chimp two will accept.
If Chimp one offers a 9/1 split, Chimp two will accept.
The chimps are rational maximizers. They don’t care how much the other chimps get, they just want to get the most food possible.
I’ve written before on how we need to stop pretending we’re rational . This research raises a lot of questions. If humans are less rational than chimps, why have we been more successful as a species.
It might not be our rationality that separates man from beast, but our irrationality. Instead of a clockwork, rule-based mind, we use heuristics, and we learn by copying those around us. Chimps might be more rational than us, but our ability to learn and copy from others makes us smarter. That’s why the next time it rains, you and I will be nice and dry in a building or under an umbrella, not shivering under a leaf.
This article is a dramatisation of the 2006 article Chimpanzees Are Rational Maximizers in an Ultimatum Game by Keith Jensen from the University of Manchester, Josep Call from the university of St Andrews, and Michael Tomasello.