1. Monkeys in a Prisoner’s Dilemma
Ju Tian, Naoshige Uchida 
Cell 
Volume 160, Issue 6, Pages (March 2015)
DOI: /j.cell
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2. Figure 1 Prisoner’s Dilemma Game
(A) An example payoff matrix of a game. There are two players (A and B), and each has to choose one of two options (C and D). Each makes a choice without knowing what the opponent will do. Depending on one’s own and the other’s choices, each receives an outcome defined by the payoff matrix (e.g., the number indicates dollar amount that each receives).
(B) The original prisoner’s dilemma game. Each prisoner is asked to either defect the other by testifying that the other committed the crime or cooperate with the other by being silent.
(C) A payoff matrix in a general form. T > R > P > S and 2R > T+S define a prisoner’s dilemma. The latter criterion guarantees that the players cannot escape the dilemma simply by taking turns.
(D) Two monkeys played an iterated prisoner’s dilemma game (defined by A in Haroush and Williams [2015]).
Cell  , DOI: ( /j.cell )
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