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Biology 202
2001 Third Web Report
On Serendip
Jack the Ripper, John Wayne Gacy, Ted Bundy, the Boston Strangler, Jeffrey Dahmer. Despite the years of history that separate these names, they remain indelibly preserved within our collective societal consciousness because of the massively violent and calculated nature of their crimes. Serial killers, both men and women, represent social monstrosities of the most terrifying variety. They are human predators, cannibals in a figurative and, often, literal sense, and are therefore uniquely subversive to society's carefully constructed behavioral tenets. They frighten because they are human in form but without the social conscience that, for many, defines humanity. They capture the public eye because they terrify, but also because they elicit a sort of gruesome curiosity about the human potential for evil; as Robert Louis Stevenson's Dr. Jekyll and Mr. Hyde alleges, wickedness lies within each heart, waiting only for the proper time and impetus to break free.
Although the behavioral patterns of serial killers have long been attributed to external (that is to say, social) causation, psychologists have recently begun to examine the biochemical circumstances underlying behavioral precursors of serial violence. A British philosopher, G.H. Lewes, noted that, " Murder, like talent, seems occasionally to run in families" (1,2). The observation, while loosely empirical in nature, has proven common enough to catalyze widespread research to identify a genetic factor resulting in a behavioral predisposition to violence. As yet, no single gene that unequivocally stimulates socially maladaptive aggression and violence has been isolated (1). However, several studies have traced psychological disorders, many of which are associated with aggression, through familial lines (4,9). A survey conducted through Boston's Children's Hospital noted a higher incidence of various psychopathologies in the families of young patients with borderline personality disorders than in families of a control group of non-pathological youths (4). Similarly, it was observed that a group of children with criminal and/or socially maladapted parents had abnormally elevated levels of social delinquency and aggression (9). The investigators conducting both studies suggest that the children's misbehavior appears genetic in origin, although it may also be the result of neglect or abuse (4,9). Although the interplay between genetics and environment in predisposing violent behavior is tightly, almost inextricably, woven, the current belief among those studying intensely violent individuals believe that "bad seeds [i.e. products of violence-predetermining genetics] blossom in bad [i.e. negligent, abusive, or violence-glamorizing] environments" (1).
Physiological deficiencies in the neurotransmitter serotonin have also been linked to psychopathologies involving excessively aggressive behavior (1,5,14). Serotonin is believed to offset the violent and aggressive effects that testosterone, the male sex hormone, has on the brain's dictation of behavior (1,5,14). Recent studies discovered that certain individuals diagnosed with violent personality disorders have both low serotonin levels and high testosterone levels (1,5,14). While the exact cause of the unusually low serotonin production is not known, a loose correlation has been made between abnormally high physiological levels of heavy metals, such as manganese, cadmium, lead, and copper, and decreased serotonin production (1). Testosterone's role in aggressive behavior has been accounted for experimentally as well as anecdotally, resulting in the observation that, "To date, across all cultures, there has been something inherently male about severe episodes of violence" [italics added] (14).
In addition to endemic pathologies, physical trauma to the brain has also been correlated with the genesis of violent behavioral tendencies like those observed in the behavioral topography of perpetrators of serial homicides (1,13). A 1986 study examined the neurological histories of fifteen death row inmates, and found that every member of the experimental population had experienced severe head injury prior to incarceration (13). Five had significant neurological impairment, seven were less intensely afflicted, six were diagnosed with schizophreniform psychoses, and two were manic-depressive (13). Because the inmates were selected without prior awareness of their mental conditions, the diversity and prevalence of these pathologies within the experimental group can be used to infer the high incidence of abnormal brain function within the population of violent offenders (13). A similar study of death-row inmates conducted by Pavlos Hatzitaskos, et. al., found that a significant percentage of those examined had endured dramatic head traumas during the course of their lives (1). The group also surveyed a population of non-inmate patients, seventy percent of whom developed violent behavior patterns after injury to the brain (1).
Brain damage in utero and in early childhood has been correlated with increased tendencies toward both youth and adult violence (1,12,14). Some of history's most notorious serial killers, Leonard Lake, David Berkowitz (a.k.a. "The Son of Sam"), Kenneth Bianchi, John Wayne Gacy, and Carl Panzram, all suffered childhood head trauma (1). Exposure of the fetal brain to toxic substances such as alcohol has also been implicated as a factor governing an individual's development of antisocial, and sometimes violent, behavioral patterns (14).
The human brain is a complex and delicate structure, and the effects of injury to its components are not fully understood. However, because control over certain behavioral traits has been assigned with reasonable assurance to specific brain structures, the effects of lesion to those regions can be predicted with a fair degree of confidence. For example, the hypothalamus contains the brain's centers for sexual response and aggression (1). Because of the physical proximity of these neuronal hubs, hypothalamic damage can result in socially destructive and violent behavior centered around an abnormal psychological connection between sexual instinct and violence (1). Both serial and single-event "lust murderers" (1) are believed to operate under analogous psychological mechanisms involving the uncontrolled encroachment of violent sexual fantasies into their comprehension of reality, coupled with the inability to separate sexual excitation from violence (11).
Because the limbic system is believed to contain structures necessary for memory, emotion, and parental and social instincts, harm to this system could result in a subject's reduced ability to engage in behavioral activities requiring those neurological processes (1). Modern societal constructs rely on their members' abilities to function within a narrowly defined set of parameters, all of which involve the cooperation of a properly functioning limbic system; therefore, its impairment duly alters an injured individual's ability to respond appropriately to social expectations. In extreme cases, this may manifest itself in acute and repetitive violence against other members of society. Similarly, damage to the temporal lobe of the brain, which can result in amnesia, epilepsy, and increased frequency and reduced threshold of violent responses, has also been implicated as a causal agent in the actions of many systematic murderers (1).
Behavioral researchers have noted a strong correlation between childhood psychopathologies and antisocial, aggressive, and repeatedly violent activity in both children and adults (2,3,6,8,10). Although periods of antisocial behavior are not uncommon among children and young adults, the persistence of intense aggression, disregard for social rules, property destruction, and pathological deceitfulness over an extended time frame indicates an increased risk for similar repeat offenses in later developmental stages (2). Certain documented childhood mental disturbances, such as Attention Deficit Disorder (ADD), are associated with a lack of behavioral restraint coupled with susceptibility to boredom, which are common to activity patterns observed in antisocial adults (2,8). Several studies suggest that childhood psychopathologies set into motion a progression of destructive behavior that perpetuates and intensifies itself in criminality within the adult behavioral repertoire (3,6,10).
There is no single organic or external origin to which serial violent behavior can be attributed. Dr. Dorothy Lewis, professor of psychiatry at NYU's School of Medicine, writes of the circumstances that promote extreme violence, "They are the combination of a history of extraordinary, early ongoing abuse, some kind of brain dysfunction and psychotic systems, particularly paranoia. The more serious the neurologic and psychotic symptomology, if the individual has been abused, the more violent the individual seems to be" (15). Equally important, the assumption that mental illness necessarily results in violent, antisocial behavior is a false one (7). In a study comparing observational data gathered from more than a thousand urban police-citizen encounters, crime patterns for the mentally ill and their non-mentally-ill counterparts were strikingly similar (7). Clearly, neither biology nor social influence alone results in the precipitation of intensely violent, antisocial behavior. Rather, it is a product, in variable proportions, of both.
Society's interaction with serial criminals, especially serial murderers, represents a dichotomy between curiosity and loathing. Stephen Sondheim's The Ballad of Sweeney Todd, a musical, mythical interpretation of the life of a serial killer who terrorized London during the late 1700s, represents modern society's tendency to transform reality into mere mirror of itself, presenting the altered, and presumably more palatable, version for public inspection (16).
The true story behind Stephen Sondheim's musical presents some of the biological and social circumstances thought to perpetuate serial violence. Sweeney Todd was born in London in 1748 into intense poverty (16). He had an abusive father and a doting mother, both of whom were alcoholics and abandoned him in the winter of his twelfth year (16). As earlier discussions would suggest, these conditions imply a significant likelihood that Todd suffered either in utero brain damage as a result of his mother's alcohol abuse or childhood head injury from his father's frequent beatings; both of these could have contributed to his future violent activities (1,12,14). At his trial, the murderer testified that his violent tendencies began at a very young age (16). He said of his mother's embraces, "I was fondled and kissed and called a pretty boy, but later I used to wish I was strong enough to throttle her" (16). This early tendency toward fantasy violence supports a connection between early-onset psychopathology and adult violent behavior (3,6,10).
After his abandonment, Todd was imprisoned for petty larceny, once again supporting the modern experimental findings that link childhood trauma, both physical and emotional, to destructive social deviance (2,3,6,8,10). Several years passed after his release before he set up his now-infamous barbershop at 186 Fleet Street in 1785 (16). Between the day he opened his shop doors and his execution in 1802, he was responsible for an estimated 160 murders (16). To avoid apprehension, he disposed his victims by transforming their bodies into meat pies, which were sold to the London public in the pie-shop of his alleged lover, Margery (a.k.a. "Sarah") Lovett (16).
Sweeney Todd's death brought about a change in the effect he had on the English populace. Because the "Demon Barber of Fleet Street" no longer posed a direct threat to anyone's safety, he became the stuff of English and international lore. Because he was no longer a man, he was transmuted into a grisly legend. Todd's representation in historical accounts, modern theater, and myth, represents the reaction of a changing society to a social deviant of dramatically violent proportions. Although significant research emphasizes the idea that violence breeds violence (1, 15), artistic representations of serial destruction readily garner support and attention. The attraction of artistically-slanted serial violence is evinced by the actions of the multitudes who flock to see The Ballad of Sweeney Todd, as well as those who read crime novels, visit gory wax museums, and huddle around desolate campfires to exchange gory tales of wicked deeds long past. Just as the exact mechanisms by which the brain of serial murderers dictate their actions remain cloaked in uncertainty, the foundations of their public appeal, when shrouded in art, persist in mystery.
1) Scott, S.L. "What Makes Serial Killers Tick?" from the Crime Library , A discussion of serial murderers and possible triggers for their behavior.
2) Ramsland, K. "The Child Psychopath: Bad Seeds or Bad Parents?" from the Crime Library , An interesting discussion of the influences of rearing, environment, and genetics on criminal tendencies.
3) Kasen, S., et. al. "Influence of Child and Adolescent Psychiatric Disorders on Young Adult Personality Disorder." Am. J. Psychiatry. 156:1529-1535. October 1999., Research showing a correlation between youthful psychiatric disorders and adult deviant behavior.
4) Goldman, S.J., E.J. D'Angelo, and D.R. DeMaso. "Psychopathology in the Families of Children with Borderline Personality Disorder." Am. J. Psychiatry. 150:1832-1835. 1993., A study recording the increased incidence of psychopathologies in children with family history of mental disturbance.
5) Brown, G.L., et. al. "Aggression, Suicide, and Serotonin: Relationships to CSF Metabolites." Am. J. Psychiatry. 139:741-746. 1982. , A study connecting low serotonin levels to increased incidence of aggression and violent behavior.
6)Kazdin, A.E. (Review of: Rapoport, Judith L. Childhood Onset of "Adult" Psychopathology: Clinical and Research Advances. Washington, D.C. American Psychiatric Press, 2000.) Am. J. Psychiatry 158:152, January 2001. , Addresses early- and late-onset psychological disturbances, and their different precursors and effects.
7) Teplin, L.A. "The Criminality of the Mentally Ill: A Dangerous Misconception." Am. J. Psychiatry. 142:593-599. 1985. , Presents evidence to counter the assumption that mental instability necessarily results in violent criminal behavior.
8) Satterfield, J.H., C.M. Hoppe, and A.M. Schell. "A Prospective Study of Delinquency in 110 Adolescent Boys with Attention Deficit Disorder and 88 Normal Adolescent Boys." Am. J. Psychiatry. 139: 795-798. 1982. , A study proposing a connection between Attention Deficit Disorder and delinquency.
9) D.O. Lewis, S.S. Shanok, and D.A. Balla. "Parental Criminality and Medical Histories of Delinquent Children." Am. J. Psychiatry. 136:288-292. 1979. , A study implicating genetics in transmission of behavioral traits.
10) Johnson, J.G., et. al. "Adolescent Personality Disorders Associated with Violence and Criminal Behavior during Adolescence and Early Adulthood." Am. J. Psychiatry. 157:1406-1412. September, 2000. , A study presenting a correlation between adult violence and previous personality disorders.
11) Prentky, R.A., et. al. "The Presumptive Role of Fantasy in Serial Sexual Homicide." J. Am. Psychiatry. 146:887-891. 1989. , Implicates an individual's "intrusive fantasy life" as a predisposing factor in serial sexual homicide.
12) Raine, A., P. Brennan, and S.A. Mednick. "Interaction between Birth Complications and Early Maternal Rejection in Predisposing Individuals to Adult Violence: Specificity to Serious, Early-Onset Violence." J. Am. Psychiatry. 154:1265-1271. 1997. , A study ultimately correlating birth complications and adult violence.
13) Lewis, D.O., et. al. "Psychiatric, Neurological, and Psychoeducational Characteristics of 15 Death Row Inmates in the United States." J. Am. Psychiatry. 143:838-845. 1986. , A study noting the prevalence of head trauma and mental illness within a population of death-row inmates.
14)) Prothow-Smith, D. and H. Spivak. "America's Tragedy." Psychiatric Times. Vol. XVI, Issue 6. June, 1999. , A survey of mounting teen violence, including a detailed discussion of several biological precursors to violent behavior patterns.
15) Grinfeld, M. J. "Executing the Mentally Ill: Who is Really Insane?" Psychiatric Times. Vol. XV, Issue 5. May, 1998. , Discussion of the legal aspects of criminal insanity and violence research.
16) Gribben, Mark. "Sweeney Todd: The Demon Barber of Fleet Street." Crime Library. , Presents facts and myths about Fleet Street's most famous serial killer.
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