Monkey Business - coursework overspill

The Ultimatum Game is (according to Jenson et al) is the "benchmark test for examining sensitivity to fairness and other-regarding preferences" (p. 107).

So lets start with the 'maths' version of the Ultimatum game:
Two participants bargain over an amount of money (or other commodity); The proposer offers a proportion of the money to the responder; if the responder accepts the offer, both participants keep their respective amounts.  If the responder rejects the offer neither player gets anything.  According to game theory both players should act in a way that maximises self interest, therefore the responder should accept any offer more than zero (as its more than he started with) and the proposer should offer the lowest amount (in order to gain the largest amount).
Unsurprisingly, in reality this doesn't happen; offers of less than 20% are only accepted about half the time and offers around 50% are accepted most of the time.  Well, that seems 'fair'!  From a multitude of experiments using the ultimatum game, across cultures and generations, it would appear that 'fairness' and cooperation is important to humans. 
Jenson et al, tested chimpanzees in the ultimatum game and found that chimps weren't concerned with fairness and would accept any non-zero offer, as game theory would predict; chimps are in fact 'rational maximisers'.  Does this suggest that humans alone have developed this sense of fairness? Brosnan et al tested Capuchin monkeys in the ultimatum game and found that they would reject 'unfair' offers, unlike the chimps; so no we are not alone.  The bargaining commodity in these studies was food an essential commodity for survival, so why might chimps 'disregard' fairness while capuchins don't?  This may be down to the societal norms that exist for the different species, chimp communities do not actively share food, they are 'individualists' for the most part, whereas capuchins are a more 'collectivist' society.
  In evolutionary terms, cooperation between kin would be beneficial to ensure survival, yet humans extend this cooperation beyond family unit. However humans will also punish individuals who violate behavioural norms, even if the individual does not benefit from correcting such behaviour.  In order for this reciprocity to be effective, humans must apply more than just mathematical models to their decision making; they must also be aware of and take into consideration the outcomes of their behaviour for themselves and others in terms of the social norms of fairness.  It has been suggested that this behaviour is unique to humans and is evidence of a 'higher mind'.
The ultimatum game represents a 'snapshot' in time, a single event divorced from other events, because of this it is not representative of everyday life.  In the standard version of the game, players remain anonymous and there is no communication between players.  In everyday life humans rely on verbal and non verbal communication to 'weigh up' others, to judge behaviours and outcomes. This brings me to another shortcoming of the ultimatum game in reflecting human behaviour; behaviours are not isolated. That is, more often than not, what we do now will impact what we and others do as a consequence. Even repeated 'one shot' games do not show these consequences to their fullest as seen in everyday life, nor do they take into consideration external and individual motivations that may well influence behaviour at any given time.  That said, the ultimatum game does show that humans do not behave according to rationalist models and highlights the fact that human behaviour is made up of a complex interaction of external and internal beliefs and motivations.