Aggression and dominance: an interdisciplinary overview

- Aggression in adults is shaped by early life experiences and other factors.
- Dominance hierarchies limit conflict escalation and maintain social stability.
- Aggressiveness in key individuals can affect group dynamics and group persistence.
- Aggression and dominance status are mediated by neuroendocrine variables.
- Social network analysis promises to enhance study of hierarchy formation.

Aggression is ubiquitous among animals, and contest outcomes in many gregarious species yield societies structured by dominance hierarchies. Recent results from a variety of disciplines have laid the groundwork for an integrative view of aggression and dominance, ranging from their physiological underpinnings to their evolutionary histories. Here we use Tinbergen's four levels of behavioral analysis to summarize our current understanding of aggressive behavior and dominance relationships. First, we discuss the role of epigenetic effects in the ontogenetic emergence of aggressive and rank-related phenotypes, and summarize how these phenotypes are mediated by endocrine and nervous system activity. We briefly review recent work on the functions of aggression and dominance hierarchies in animal societies, and then consider their phylogenetic history. Finally, we review methodological encumbrances to the study of dominance, and consider the unique evolution of aggression and dominance relationships in humans.