219465504-Evolution and Behavioral Genetics
From PsychWiki - A Collaborative Psychology Wiki
Section 1
Violence is defined as an act that results in physical harm and it is not a rare event in our society. We are exposed to violence so much through the media and in daily life that we have become desensitized to it. When we were first exposed to violence we may have felt fear, but after being exposed to violence for so long, it has become so common that we may not feel that same way. Violent acts in neighborhoods run by gangs may be so common that the people living in those areas are not surprised, but still saddened, by fatalities that are gang related. Researchers specializing in different fields of science have come together in search of finding explanations for violence. Two themes that have been explored as possible causes of violence are evolution and behavioral genetics.
Social psychologists have turned to evolutionary theories to try and explain how interpersonal violence may have been beneficial for survival over evolutionary time, but the theories have weak connections to human aggression (McCall 2008). Humans do act violently to protect scarce resources(ex: drugs wars) and they may fight to secure their reproductive success (ex: two men engaging in a fight over a woman’s love) but these evolutionary theories still do not give good explanations for all violent behavior in our modern world. Rather, evolution seems to play a role in the predisposition that humans have for responding to situations in violent ways (McCall 2008)
Behavioral genetic researchers have the task of studying how much of human behavior can be attributed to genetics and how much of it can be contributed to the environment (Hines 2002). Studies are conducted by comparing pairs of individuals who share genetics and/or environment. The studies have three basic designs: family, twin, and adoption.
Tehrani and Brennan (1998) hypothesized that violent offending and mentally ill parents may genetically predispose their children to criminal violence through prenatal disturbances in fetal development. They reported that in an earlier study, individuals that had since birth been separated from a schizophrenic mother were later in life more likely to be criminals and engage in violent behavior. To researchers it suggested that there was a genetic link between the mother’s mental illness and the offspring’s criminal behavior. Tehrani and Brennan also found that mothers who had been exposed to influenza during the second-trimester of pregnancy had higher rates of children in adulthood experiencing schizophrenia. The researchers suggest that the influenza may have disrupted the neurological development of the fetus in a critical point of development. Individuals with schizophrenia are known to be more paranoid, which can elevate violent behavior. In the same report, Tehrani and Brennan concluded that mothers with mental illness, personality disorders, a history of alcoholism, or a history of suicide attempts are all likely to have children with higher rates of violent criminal behavior.
In a child twin study (Deater-Deckard 2007), it was found that twins who had been separated at birth and exposed to different environmental influences still had similar temperaments. Genetics were correlated with behavioral problems, anger, and frustration, but little research has been done on how the genetics operate to explain such correlations. In individuals with antisocial disorder, having a biological relative that is an alcoholic explains more of the variance than living in an unstable environment (DiLalla 1991). The same evidence was found in adoption studies, where researchers found that even if a child was born of an alcoholic parent or parents but adopted from a very young age into a stable home with nonalcoholic parents, the child was more likely to be a criminal later in life (DiLalla 1991). In another study, minor physical anomalies resulting from pregnancy complications were found to be related to violent offenses in males, but only if they had an unstable upbringing (DiLalla 1991).
There is enough evidence to suggest that genetics influence aggression, but have researchers found ways to use genetics to reduce violence? According to McCall (2007), violence is a result of biological, environmental, and situational inputs and violence can be prevented by dealing with the external influences. Deater-Deckard (2007) also reported that manipulating an individual’s environment can alter underlying behaviors. Whether there was genetic error during fetal development or inheritance from a parent, there is no way to change genetic makeup once the individual is born, but medications can be given to violent offenders that may change their brain chemistry to reduce violent behavior.
Section 2
Willamette Week, a newspaper in Portland, Oregon, published a story on December 2,1998, about a 20 year old man that committed violent acts upon himself. Peter Klarquist had been sent to jail after running his car into five other cars at a stoplight. Although it was suspected that he was trying to commit suicide, he was charged with 13 offenses, including second-degree assault. He pleaded guilty but claimed insanity as a defense. He would be committed to Oregon State Hospital, but due to improperly filled out paperwork, he was sent to wait in a jail cell. In that cell, Klarquist gouged one of his eyes out with his bare hands. All he could say to the jailer who found him later that day was, “I think I clawed my eye out”. Two days later, in a hospital, he did it again, to his other eye, and is now legally blind.
Klarquist was said to have been normal growing up. He was a middle child, held part time jobs, and even had an Eagle Scout badge. Midway through high school he was diagnosed with depression, bipolar disorder, and later in life he was diagnosed as schizophrenic. After hearing of the violent act that his son had committed on himself, Klarquist’s father said that he believed his son “was hearing voices and the voices told him to do that”.
Section 3
Peter Klarquist had a history of depression and his own family suspected he was schizophrenic. Although his family history was not revealed and it was not noted if his brothers, too, had mental illness, it is likely that his mother may have suffered from depression since, according to womenhealthfocus.com, depression is often found in several family members, meaning it could be genetically linked, and occurs in women twice as often as men. It is also possible that sometime during a critical stage in Klarquists’ fetal development genetic errors occurred which later in life caused him, but not his brothers, to become schizophrenic.
The jail staff was aware of Klarquist’s mental illness, but did not arrange for extra supervision near his jail cell. His family was aware of his illness history, so it is likely that Klarquist was on medication, but as noted earlier, medicines can only affect chemistry to reduce violent behavior. There was no way to change his genetic makeup to avoid his depression and schizophrenia in the first place.
Section 4
On April 20, 1999, in Littleton, Colorado, Eric Harris and Dylan Klebold went on a school shooting rampage that lasted almost 50 minutes. 12 people were killed and 23 others were injured. Harris and Klebold then killed themselves. The original plan for the boys was to kill many more people with explosives, but the plan failed. Contrary to popular belief, the boys did not target a specific group of people or have a hit list. They planned to kill everyone, including friends, so that their names would never be forgotten. Evolution might not help explain this incident, but genetics can.
According to reports, Dylan Klebold was anxious, paranoid, lonely and depressed. In his journals he wrote of his life being “the most miserable existence in the history of time” and he referred to himself as “a god of sadness”. He also believed that he had always “been hated by everyone and everything”, although reports show that the teens were not at all loners, outcasts, or the target of bullies. Dylan’s parents were described as “a well-educated…highly intelligent couple” that spent time with their son, they had no idea he was suicidal. Dylan’s depression could be traced back to genetic influences. His mother could have a history of depression, making it likely that Dylan could have been exposed to some gene associated with depression while he was still in fetal development. If Dylan’s mother did not realize he was depressed, there is a chance that maybe she didn’t have a history of depression, but other members of the family could have a history of depression or anger issues, making it likely that Dylan was genetically exposed to it. Along some crucial point in fetal development there could have also been fetal exposure to drugs or alcohol by the mother or genetic errors that would later cause Dylan to be slightly schizophrenic, causing him to be paranoid. Maybe his mother was an alcoholic or did drugs and that exposure to the fetus would damage him later in life.
Eric Harris was very different from Dylan, this teenager was actually seen as a “psychopath” by some psychologists who later reviewed the case. They said he was “controlling, manipulative, and sadistic”. He was a smart teenager who took advantage of his ability to charm and lie to adults, when in fact he despised authority and wanted control. While Dylan felt he was “ a god of sadness”, Eric saw himself as a God and wanted to have “everyone being officially lower” than him. Eric had severe issues with anger and it would not be wrong to assume that he might have been genetically exposed to a disorder early in fetal development. He may have even suffered a strong blow to the front part of his brain early in childhood, causing permanent damage and affecting his inability to cope, which could have led to his violence. Eric’s parents and other family members could also have been very violent people also and this family could have predisposition to violence. Regardless of underlying factors, it is important to note that outside factors are what pushed the boys to their breaking point. Eric wrote in one of his last journal entries that he was angry for being left out of so many fun things. The teenagers had friends, but they were not accepted by who they thought mattered most.
How could evolution and behavioral genetics have been used to prevent the tragedy at columbine? Parents should be mandated to fill out a survey when enrolling their children in school. Parents can also wish to remain anonymous. Surveys should ask questions such as:
Did the mother use drugs during her pregnancy that could have affected the fetus?
Are there any family members that have a history of having anger issues or being depressed or have mental illness?
Does the student currently show symptoms of depression or anger?
Parents should be encouraged to answer honestly since the surveys can be anonymous. School officials then have an idea of how many at risk students they have in the school. Those parents who did not wish to remain anonymous can ask school counselors to sit down and talk with their child at least once a month if they are at risk. When school counselors know that there are at risk students based on the surveys but don’t know who they are, teachers must then be trained in looking for signs of depression or anger in their students work. Since students like Eric Harris can fool teachers with their talent and charms, English professors should encourage their students to do more creative writing to make their work more personal. More questions such as, “what is your opinion of this topic?” or “have you ever been in a similar situation? If so, how did it make you feel?” should be asked. When a student is encouraged to express their personal opinion, the professors might find signs of mental disturbances that can be reported to school officials for investigation or further questioning so that another school tragedy can be prevented.
References
Deater-Deckard, K., Petrill, S.A., & Thompson, L.A. (2007). Anger/frustration, task persistence, and conduct problems in childhood: a behavioral genetic analysis. Journal of Child Psychology and Psychiatry, 48, 80-87.
DiLalla, L.F., & Gottesman, I.I. (1991). Biological and genetic contributors to violence-Widom’s untold tale. Psychological Bulletin, 109, 125-129.
Hines, D.A., & Saudino, K.J. (2002). Intergenerational transmission of intimate partner violence: A behavioral genetic perspective. Trauma, Violence, & Abuse, 3, 210-225.
McCall, G.S., & Shields, N. (2008). Examining the evidence from small-scale societies and early prehistory and implications for modern theories of aggression and violence. Aggression and Violent Behavior, 13, 1-9.
O’Hagan, M. (December 2, 2008). Blind injustice. Retrieved May 12, 2009, from http://wweek.com/html/crime120298.html
Tehrani, J.A, Brennan, P.A., & Hodgins, S. (1998). Mental illness and criminal violence. Soc Psychiatry Psychiatr Epidemiol, 33, 81-85.
◄ Back to How to explain violent behavior? page
