The basic problem in an evolutionary transition in complexity is to understand how a group of individuals becomes a new kind of individual, having heritable variation in fitness at the new level of organization. We see the formation of cooperative interactions among lower-level individuals as a necessary step in evolutionary transitions; only cooperation transfers fitness from lower levels (cos...

THE ABSTRACT COULD BE REWRITTEN EMPHASIZING THE TRADITIONAL DIFFICULTIES IN FINDING A RELATION BETWEEN INEQU. AND CONFLICT AND OUR EXPLANATION FOR THAT. Most empirical studies on civil conflict are not able to find a significant relationship between interpersonal-measures of economic inequality and the likelihood of conflict. When individuals belong to groups, general inequality (measured by th...