http://www.nytimes.com/2014/04/01/science/spite-is-good-spite-works.html
Although groups of excessively spiteful or selfish players quickly collapsed, and rigidly fair-minded societies were readily destabilized by influxes of selfish exploiters, the flexible sharers not only proved able to coexist with the spiteful types, but the presence of spitefuls had the salubrious effect of enhancing the rate of fair exchanges among the genials. By the looks of it, Dr. Smead said, “fairness is acting as a defense against spite.”
The results echo other recent research suggesting that human decency and cooperation require a certain degree of so-called altruistic punishment: the willingness of some individuals to punish rule breakers even when the infraction does not directly affect them — challenging the guy who broke into the line behind you, for example.
Zipczyk - Worth a Second Look 