Supremacy of a Social Network

In a New York Times article (March 14, 2011, Nicholas Wade quotes Kim Hill, a social anthropologist at Arizona State University, who states that "The ability to cooperate, to make individuals subordinate their strong self-interest to the needs of the group, lies at the root of human achievement.  We have rockets because 10,000 people cooperate in producing the information."  In Dr, Hill;s views, Underlying human evolutionary success is the unusual ability of non-relatives to cooperate--in almost all other species, only closely related individuals will help each other.