: (That link didnt work for me) : : Yup. As Axelrod showed, the optimal strategy in a repeated-iteration Prisoner's Dilemma is tit-for-tat starting with co-operation, not competition.
: But the moment someone 'cheats' for extra points its ruined.....
But that's the point...
You might try a page from the Libertarian Alliance
http://www.globalideasbank.org/BI/BI-36.HTML
(I won't launch into my evolutionary psychology schtick)