Editing Aggression (section)

===Within a group===
Aggression between conspecifics in a group typically involves access to resources and breeding opportunities. One of its most common functions is to establish a [[dominance hierarchy]]. This occurs in many species by aggressive encounters between contending males when they are first together in a common environment.<ref name="adamsonetal2006">{{cite journal |pmid=10574728 |url=http://jeb.biologists.org/cgi/pmidlookup?view=long&pmid=10574728 |year=1999 |last1=Issa |first1=F. A. |title=Dominance hierarchy formation in juvenile crayfish procambarus clarkii |journal=The Journal of Experimental Biology |volume=202 |pages=3497–506 |last2=Adamson |first2=D. J. |last3=Edwards |first3=D. H. |issue=24|doi = 10.1242/jeb.202.24.3497| bibcode=1999JExpB.202.3497I |url-access=subscription }}</ref> Usually the more aggressive animals become the more dominant.<ref>{{cite journal |doi=10.1016/j.beproc.2006.05.004 |pmid=16815645 |title=Social relationships in a herd of Sorraia horses |journal=Behavioural Processes |volume=73 |issue=2 |pages=170–7 |year=2006 |last1=Heitor |first1=Filipa |last2=Oom |first2=Maria do Mar |last3=Vicente |first3=Luís |s2cid=24008518 }}</ref><ref>{{cite journal |doi=10.1086/503445 |pmid=16615035 |title=Individual Variation in Social Aggression and the Probability of Inheritance: Theory and a Field Test |journal=The American Naturalist |volume=167 |issue=6 |pages=837–52 |year=2006 |last1=Cant |first1=Michael A. |last2=Llop |first2=Justine B. |last3=Field |first3=Jeremy |bibcode=2006ANat..167..837C |hdl=10871/26263 |s2cid=12094679 |url=https://ore.exeter.ac.uk/repository/bitstream/10871/26263/1/CantetalAggression06AmNat.pdf |hdl-access=free }}</ref> In test situations, most of the conspecific aggression ceases about 24 hours after the group of animals is brought together.<ref name="adamsonetal2006"/><ref>{{cite journal |pmid=16869278 |year=2006 |last1=Bragin |first1=A. V. |title=The experimental model of establishment and maintenance of social hierarchy in laboratory mice |journal=Zhurnal Vysshei Nervnoi Deiatelnosti imeni I P Pavlova |volume=56 |issue=3 |pages=412–9 |last2=Osadchuk |first2=L. V. |last3=Osadchuk |first3=A. V. }}</ref> Aggression has been defined from this viewpoint as "behavior which is intended to increase the social dominance of the organism relative to the dominance position of other organisms".<ref name="Ferguson & Beaver, 2009">{{cite journal |doi=10.1016/j.avb.2009.03.005 |title=Natural born killers: The genetic origins of extreme violence |journal=Aggression and Violent Behavior |volume=14 |issue=5 |pages=286–94 |year=2009 |last1=Ferguson |first1=Christopher J. |last2=Beaver |first2=Kevin M. }}</ref> Losing confrontations may be called [[social defeat]], and winning or losing is associated with a range of practical and psychological consequences.<ref>{{cite journal |doi=10.1017/S146479310500686X |pmid=16460581 |title=Modulation of aggressive behaviour by fighting experience: Mechanisms and contest outcomes |journal=Biological Reviews |volume=81 |issue=1 |pages=33–74 |year=2005 |last1=Hsu |first1=Yuying |last2=Earley |first2=Ryan L. |last3=Wolf |first3=Larry L. |s2cid=14284236 |doi-access=free }}</ref>

Conflicts between animals occur in many contexts, such as between potential mating partners, between parents and offspring, between siblings and between competitors for resources. Group-living animals may dispute over the direction of travel or the allocation of time to joint activities. Various factors limit the escalation of aggression, including communicative displays, conventions, and routines. In addition, following aggressive incidents, various forms of [[conflict resolution]] have been observed in mammalian species, particularly in gregarious primates. These can mitigate or repair possible adverse consequences, especially for the recipient of aggression who may become vulnerable to attacks by other members of a group. Conciliatory acts vary by species and may involve specific gestures or simply more proximity and interaction between the individuals involved. However, conflicts over food are rarely followed by post conflict reunions, even though they are the most frequent type in foraging primates.<ref>{{cite journal |doi=10.1006/anbe.2002.3071 |title=Conflict resolution following aggression in gregarious animals: A predictive framework |journal=Animal Behaviour |volume=64 |issue=3 |pages=325–43 |year=2002 |last1=Aureli |first1=Filippo |last2=Cords |first2=Marina |last3=Van Schaik |first3=Carel P. |s2cid=54361369 }}</ref>

Other questions that have been considered in the study of primate aggression, including in humans, is how aggression affects the organization of a group, what costs are incurred by aggression, and why some primates avoid aggressive behavior.<ref>Silverberg, James; J. Patrick Gray (1992) ''[https://books.google.com/books?id=5CQW4vPNH-EC Aggression and Peacefulness in Humans and Other Primates]'' {{ISBN|0-19-507119-0}}</ref> For example, [[Bonobo|bonobo chimpanzee]] groups are known for low levels of aggression within a partially [[matriarchal]] society. [[Captivity (animal)|Captive]] animals including primates may show abnormal levels of social aggression and self-harm that are related to aspects of the physical or social environment; this depends on the species and individual factors such as gender, age and background (e.g., raised wild or captive).<ref>{{cite journal |doi=10.1016/j.neubiorev.2005.05.002 |pmid=16055188 |title=Enrichment and aggression in primates |journal=Neuroscience & Biobehavioral Reviews |volume=30 |issue=3 |pages=413–36 |year=2006 |last1=Honess |first1=P.E. |last2=Marin |first2=C.M. |s2cid=33130527 }}</ref>