Page 7 - Science Focus (issue20)
P. 7

You might think life is quite far from being a        From this table, we know that the Japanese will take
        confession or coin-betting game, but game theory is   the North route to minimize the days of possible attack
        remarkable in that it straddles the boundaries between   from the Americans (footnote 3); while no routes seem
        math and social sciences – theorists have studied     particularly advantageous, the better route for the
        decisions made in history using game theory. A notable   American navy, therefore, is also the North route based
        example is, unsurprisingly, from World War II, where there   on the inference above. In fact, this is exactly what
        is often no room for collaboration between enemies,   happened; the Allied forces sustained an air attack on
        and so war is the perfect textbook example in looking   the Japanese over two days, and ended up resisting
        for an equilibrium. This results in a zero-sum game, when   the Japanese invasion into New Guinea. Game theory is
        your opponent's gain is your loss, and vice versa. Here,   powerful in this way – it extends far beyond just numbers,
        unlike in the prisoner’s dilemma above, cooperation is   into the realms of disciplines such as history and biology.
        simply not an option.
                                                                  Then, you might ask, what should we do in situations
            In the Battle of the Bismarck Sea, a Japanese     like this? In truth, life is almost never a zero-sum game,
        admiral was forced to choose between two different    although the zero-sum game mindset is a common
        routes, North and South [4]. The American general,    belief among people [3]. You don’t have to win at the
        George Kenney, tried to predict which route the       expense of others – there is always a win-win solution.
        Japanese would take, so that they could coordinate    As much as I sound like an old person, look for these
        a more persistent bomb attack on the Japanese         win-win situations. There is almost always room to
        Navy. Basically, the Japanese aimed at minimizing the   compromise, and you don’t need to put people down
        number of days of being bombed; but the American      in order to pull yourself up.
        would like to maximize the duration of the attack. Both
        routes would take three days but American’s action was
        restricted by various limitations, such as poor visibility on
        the North route. The table for the scenario looks like this:  1   The Nash equilibrium is named after John Nash (1928–2015), a
                                                                mathematician who made important contributions to game
                                                                theory and geometry; the former won him the Nobel Prize for
         Possible days for attack  Japanese: North  Japanese: South  Economics in 1994. He was also portrayed in the film, A Beautiful
           American: North      2 days          2 days        2  You may want to try out the simulator itself; the prisoner’s dilemma
                                                                simulator that inspired this article is
           American: South      1 day           3 days
                                                              3   If we think from the Japanese’s perspective, both routes are
                                                                equally risky if the American chooses the North route, but the
                                                                North route will become less dangerous if the American picks the
                                                                South route.  As a result, the North route is more favorable for the

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