### Ideas from 'Prisoner's Dilemma' by William Poundstone [1992], by Theme Structure

#### [found in 'Prisoner's Dilemma' by Poundstone,William [OUP 1992,0-19-286162-x]].

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###### 23. Ethics / B. Contract Ethics / 1. Contractarianism
 22717 Self-interest can fairly divide a cake; first person cuts, second person chooses
 Full Idea: To fairly divide a cake between two children, the first divides it and the second chooses. …Even division is best, as it anticipates the second child will take the largest piece. Fairness is enforced by the children's self-interests. From: William Poundstone (Prisoner's Dilemma [1992], 03 'Cake') A reaction: [compressed] This is introduced as the basic principle of game theory. There is an online video of two cats sharing a dish of milk; each one drinks a bit, then pushes the dish to the other one. I'm sure two children could manage that.
###### 23. Ethics / B. Contract Ethics / 6. Game Theory
 22718 Formal game theory is about maximising or minimising numbers in tables
 Full Idea: At the most abstract level, game theory is about tables with numbers in them - numbers that entities are are efficiently acting to maximise or minimise. From: William Poundstone (Prisoner's Dilemma [1992], 03 'Curve') A reaction: A brilliant idea. The question is the extent to which real life conforms to the numberical tables. The assumption that everyone is entirely self-seeking is blatantly false. Numbers like money have diminishing marginal utility.
 22719 The minimax theorem says a perfect game of opposed people always has a rational solution
 Full Idea: The minimax theorem says that there is always a rational solution to a precisely defined conflict between two people whose interests are completely opposite. From: William Poundstone (Prisoner's Dilemma [1992], 03 'Minimax') A reaction: This is Von Neumann's founding theorem of game theory. It concerns maximising minimums, and minimising maximums. Crucially, I would say that it virtually never occurs that two people have completely opposite interests. There is a common good.
###### 23. Ethics / B. Contract Ethics / 7. Prisoner's Dilemma
 22721 The tragedy in prisoner's dilemma is when two 'nice' players misread each other
 Full Idea: The tragedy is when two 'nice' players defect because they misread the other's intentions. The puzzle of the prisoner's dilemma is how such good intentions pave the road to hell. From: William Poundstone (Prisoner's Dilemma [1992], 11 'Howard's') A reaction: I really wish these simple ideas were better known. They more or less encapsulate the tragedy of the human race, with its inability to prioritise the common good.
 22720 Two prisoners get the best result by being loyal, not by selfish betrayal
 Full Idea: Prisoners A and B can support or betray one another. If both support, they each get 1 year in prison. If one betrays, the betrayer gets 0 and the betrayed gets 3. If they both betray they get 2 each. The common good is to support each other. From: William Poundstone (Prisoner's Dilemma [1992], 06 'Tucker's') A reaction: [by Albert Tucker, highly compressed] The classic Prisoner's Dilemma. It is artificial, but demonstrates that selfish behaviour gets a bad result (total of four years imprisonment), but the common good gets only two years. Every child should study this!
###### 23. Ethics / B. Contract Ethics / 8. Contract Strategies
 22723 Do unto others as you would have them do unto you - or else!
 Full Idea: TIT FOR TAT threatens 'Do unto others as you would have them do unto you - or else!'. From: William Poundstone (Prisoner's Dilemma [1992], 12 'TIT') A reaction: Essentially human happiness arises if we are all nice, but also stand up firmly for ourselves. 'Doormats' (nice all the time) get exploited. TIT FOR TAT is weak, because it doesn't exploit people who don't respond at all.
 22722 TIT FOR TAT says cooperate at first, then do what the other player does
 Full Idea: The successful TIT FOR TAT strategy (for the iterated prisoner's dilemma) says cooperate on the first round, then do whatever the other player did in the previous round. From: William Poundstone (Prisoner's Dilemma [1992], 12 'TIT') A reaction: There are also the tougher TWO TITS FOR A TAT, and the more forgiving TIT FOR TWO TATS. The one-for-one seems to be the main winner, and is commonly seen in animal life (apparently). I recommend this to school teachers.