Games and Guardians 149Whatever you choose, you have to live with the conse-
quences, but this is a hypothetical situation, to demonstrate
the intricacies of trust and co-operation versus mistrust and
non-cooperation. In a one-off play, when you have no extra
information, the only rational choice is to defect and inform
on your partner. But trust or mistrust comes down to a rela-
tionship, so it is more realistic to play the prisoner’s dilemma
game many times to find the best strategy over time.
We keep having to make the same kind of decision – can
I trust you? – but with different people each time. Everyone
has a ‘trust trail’, either a reputation for keeping their word
or a trail of broken promises. If you can, you look at some-
one’s previous track record before deciding whether to trust
them. If you do not know their track record, then you have
to make a best guess that depends on the circumstances and
how much you have to lose.
The prisoner’s dilemma game was played as part of re-
search into game theory in the 1970s. Game theory is far
from playful, it studies how we make alliances and come to
decisions about our best moves when we do not have all the
available information. Depending on the rules of the game,
some moves gain an advantage, while others lose. To do well
in any game, whether it is a friendly game of Monopoly (if it
is possible to have a friendly game of Monopoly) or running
an international business, you need to know the rules. Every-
one has to obey the rules or there can be no game. Even
international summit meetings have rules. Game theory
deals with situations where there are rules and the insights
were used to try to resolve the real-life political deadlocks of
the time: the Cold War and the Arab–Israeli stalemate.
In the late 1970s a political researcher named Robert
Axelrod wanted to find out the best strategy for winning at
prisoner’s dilemma, so he devised a computer tournament
in Michigan. Anyone could enter a computer program
that would take the place of one of the prisoners. The pro-
grams would participate in an all-play-all tournament,
known as ‘iterated prisoner’s dilemma’. Each game with
an opposing computer would consist of 200 moves, giving