Editing Serial killer (section)

===Theories===

====Biological and sociological====
Theories for why certain people commit serial murder have been advanced. Some theorists believe the reasons are biological, suggesting serial killers are born, not made, and that their violent behavior is a result of abnormal brain activity. Holmes believes that "until a reliable sample can be obtained and tested, there is no scientific statement that can be made concerning the exact role of [[biology]] as a determining factor of a serial killer personality."{{sfn|Holmes|Holmes|2010|pp=55–56}}

The "Fractured Identity Syndrome" (FIS) is a merging of [[Charles Cooley]]'s "[[looking glass self]]" and [[Erving Goffman]]'s "virtual" and "actual social identity" theories. The FIS suggests a social event, or series of events, during one's childhood results in a fracturing of the personality of the serial killer. The term "fracture" is defined as a small breakage of the personality which is often not visible to the outside world and is only felt by the killer.<ref>{{cite web|url=http://fbilibrary.fbiacademy.edu/bibliographies/serialkillers.htm |title=Serial Killers  |publisher=[[Federal Bureau of Investigation]] |access-date=May 26, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100520203225/http://fbilibrary.fbiacademy.edu/bibliographies/serialkillers.htm |archive-date=May 20, 2010 }}</ref>

"Social Process Theory" has also been suggested as an explanation for serial murder. Social process theory states that offenders may turn to crime due to peer pressure, family and friends. Criminal behavior is a process of interaction with social institutions, in which everyone has the potential for criminal behavior. A lack of family structure and identity could also be a cause leading to serial murder traits. A child used as a scapegoat will be deprived of their capacity to feel guilt. Displaced anger could result in animal torture, as identified in the [[Macdonald triad]], and a further lack of basic identity.{{sfn|Claus|Lindberg|1999|pp=427–435}}

====Military====
[[File:Charles Ng.jpg|thumb|150px|A dishonorably discharged Marine, [[Charles Ng]] participated in the kidnapping, sadistic torture, rape, and murder of numerous victims.]]

The "military theory" has been proposed as an explanation for why serial murderers kill, as some serial murderers have served in the military or related fields. According to Castle and Hensley, 7% of the serial killers studied had military experience.<ref>{{harvnb|Castle|Hensley|2002|pp=453–465}}, {{harvnb|DeFronzo|Prochnow|2004|pp=104–108}}</ref> This figure may be a proportional under-representation when compared to the number of military veterans in a nation's total population. For example, according to the United States census for the year 2000, military veterans comprised 12.7% of the U.S. population;<ref>{{Cite web|last1= Richardson |first1= Christy |last2= Waldrop |first2= Judith |title= Veterans: 2000 |url= https://www.census.gov/prod/2003pubs/c2kbr-22.pdf |publisher= U.S. Census Bureau |year= 2003 |access-date= July 13, 2011 |page= 5 |journal=  |archive-date= August 25, 2011 |archive-url= https://web.archive.org/web/20110825194126/http://www.census.gov/prod/2003pubs/c2kbr-22.pdf |url-status= live }}</ref> in England, it was estimated in 2007 that military veterans comprised 9.1% of the population.{{sfn|Woodhead|Sloggett|Bray|Bradbury|2009|pp=50–54}} Though by contrast, about 2.5% of the population of Canada in 2006 consisted of military veterans.<ref>{{cite web|url=http://www.statcan.gc.ca/pub/98-187-x/4151287-eng.htm#table3|title=Estimated population of Canada, 1605 to present|date=July 6, 2009|publisher=Statistics Canada|access-date=May 23, 2011|archive-date=June 30, 2019|archive-url=https://wayback.archive-it.org/all/20190630114202/https://www150.statcan.gc.ca/n1/pub/98-187-x/4151287-eng.htm#table3|url-status=live}}</ref><ref>{{cite web|title=The Veteran Population and the People We Serve |url=http://www.veterans.gc.ca/eng/sub.cfm?source=department%2Freports%2Ffiveyearplan03%2Fplan03_population |year=2003 |work=Veterans Affairs Canada |access-date=July 13, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20121001151839/http://www.veterans.gc.ca/eng/sub.cfm?source=department%2Freports%2Ffiveyearplan03%2Fplan03_population |archive-date=October 1, 2012 }}</ref>

There are two theories that can be used to study the correlation between serial killing and military training: ''Applied learning theory'' states that serial killing can be learned. The military is training for higher kill rates from servicemen while training the soldiers to be desensitized to taking a human life.{{sfn|Castle|Hensley|2002}} ''Social learning theory'' can be used when soldiers get praised and accommodated for killing. They learn or believe that they learn, that it is acceptable to kill because they were praised for it in the military. Serial killers want accreditation for the work that they have done.<ref name="Exploring">{{cite web |url=http://www.deviantcrimes.com/serialmurder_sociallearning.htm |title=Social Learning and Serial Murder |website=www.deviantcrimes.com |access-date=15 January 2022 |archive-url=https://web.archive.org/web/20090104221523/http://www.deviantcrimes.com/serialmurder_sociallearning.htm |archive-date=4 January 2009 |url-status=dead}}</ref>

In both military and serial killing, the offender or the soldier may become desensitized to killing as well as compartmentalized; the soldiers do not see enemy personnel as "human" and neither do serial killers see their victims as humans.{{sfn|Hamamoto|2002|pp=105–120}} The theories do not imply that military institutions make a deliberate effort to produce serial killers; to the contrary, all military personnel are trained to recognize when, where, and against whom it is appropriate to use deadly force, which starts with the basic ''[[Laws of war|Law of Land Warfare]]'', taught during the [[Recruit training|initial training phase]], and may include more stringent policies for military personnel in law enforcement or security.{{sfn|Atwood|1992}}