Editing Aggression (section)

===Violence and conflict===
Aggression can involve [[violence]] that may be [[Adaptation|adaptive]] under certain circumstances in terms of [[natural selection]]. This is most obviously the case in terms of attacking prey to obtain food, or in anti-predatory defense. It may also be the case in competition between members of the same species or subgroup, if the average reward (e.g., status, access to resources, protection of self or kin) outweighs average costs (e.g., injury, exclusion from the group, death). There are some hypotheses of specific adaptions for violence in humans under certain circumstances, including for [[homicide]], but it is often unclear what behaviors may have been selected for and what may have been a byproduct, as in the case of collective violence.<ref>Buss, D.M. (2005). ''[https://books.google.com/books/about/The_Murderer_Next_Door.html?id=NEq9TTBbt64C The murderer next door: Why the mind Is designed to kill]''. New York: Penguin Press.</ref><ref>{{cite journal |doi=10.1016/j.avb.2007.04.001 |title=Examining the evidence from small-scale societies and early prehistory and implications for modern theories of aggression and violence |journal=Aggression and Violent Behavior |volume=13 |issue=1 |pages=1–9 |year=2008 |last1=McCall |first1=Grant S. |last2=Shields |first2=Nancy }}</ref><ref>{{cite book |last1=Buss |first1=D. M. |last2=Duntley |first2=J. D. |chapter-url=http://psycnet.apa.org/psycinfo/2006-20303-012 |chapter=The evolution of aggression |year=2006 |editor1-first=M. |editor1-last=Schaller |editor2-first=J. A. |editor2-last=Simpson |editor3-first=D. T. |editor3-last=Kenrick |title=Evolution and Social Psychology |pages=263–86 |location=New York |publisher=Psychology Press }}</ref><ref>{{cite journal |doi=10.1016/j.avb.2011.04.014 |title=Collective violence: An evolutionary perspective |journal=Aggression and Violent Behavior |volume=16 |issue=5 |pages=428–36 |year=2011 |last1=Durrant |first1=Russil }}</ref>

Although aggressive encounters are ubiquitous in the animal kingdom, with often high stakes, most encounters that involve aggression may be resolved through posturing, or displaying and trial of strength. [[Game theory]] is used to understand how such behaviors might spread by [[natural selection]] within a population, and potentially become 'Evolutionary Stable Strategies'. An initial model of resolution of conflicts is the [[hawk-dove game]]. Others include the [[Risk management|Sequential assessment model]] and the [[Attrition warfare|Energetic war of attrition]]. These try to understand not just one-off encounters but protracted stand-offs, and mainly differ in the criteria by which an individual decides to give up rather than risk loss and harm in physical conflict (such as through estimates of [[resource holding potential]]).<ref>{{cite journal |last1=Briffa |first1=Mark |year=2010 |url=http://www.nature.com/scitable/knowledge/library/territoriality–and–aggression–13240908 |title=Territoriality and Aggression |journal=Nature Education Knowledge |volume=3 |issue=10 |pages=81 }}</ref>