PSYCHOLOGY - Altruistic side of aggressive greed

In many group-living species, high-rank individuals bully their group-mates to get what they want, but their contribution is key to success in conflict with other groups, according to a study that sheds new light on the evolutionary roots of cooperation and group conflict. In a series of mathematical models, researchers uncovered a mechanism for explaining how between-group conflict influences within-group cooperation and how genes for this behav ...

http://www.sciencedaily.com/releases/2014/03/140326092600.ht