The authors of the essays presented in this collection use selected animal and human models to inquire into the dynamics of hierarchical behavior. The collection begins with a review of the biological parameters of human behavior and suggests that a biological basis can be found in association with general strategies for organizing human behavior. Barchas has organized the essays proceeding from an evolutionary contextual frame through contributions that illuminate the regulation of hierarchical structures, to the final essays that implicate the brain's attentional system as a chief mediator between an individual's position in the group structure and behavior. This provocative volume presents strategies for thinking about some of the issues that necessarily arise when the impact of social behavior, physiology, and evolution on hierarchical behavior is considered.