The Nature of Human Aggression

I. Introduction
We are exploring the differences in the roles heredity and environment play in human aggression. This is not an easy question, one that the scientific community has been grappling for years. The current consensus seems to be that both heredity and environment play significant roles in determining our intricate personalities, including the areas of violence and aggression. Through a survey we will conduct later in the semester, we will question Miami students about their childhood, criminal background, and past incidents of violence among other things, to attempt to determine whether their genetic makeup or rearing had a greater influence on possible violent behavior. We expect to find that both genetics and environment play significant yet undefined roles in determining aggressiveness in human personalities, along with all other traits.
Controversy surrounds the origins of human aggression. Biologists' viewpoints will suggest that humans share certain "genetically determined tendencies" toward aggressive behavior. The behaviorist argument suggests that aggression is acquired through experience, and learning. However, we hope to prove that the two are not mutually exclusive of one another. Some aggressions found in humans have biological origins and some are learned.

II. Relevance
Through out our research we have encountered various experiments and much insight into how environment and genetics play a role in the development of aggression in humans. Author of the book Human Aggression, Russel Geen, defines aggression as a noxious stimulus to another person with the intent of harming that person, and in the expectation that the aversive stimulus will reach its destination. This may lead some to ask, "what the hell is this guy talking about." The answer is simple. According to Lee Ellis, aggression is wanting to hurt someone or something and then acting accordingly; expecting they will get hurt. Then there are many different types of behavior that fit the definition of aggression, thus it is best for us to recognize that there are different types of aggression, the major two being affective and instrumental aggression. Affective aggression is simply anger, its main goal injury or harm. Instrumental aggression is recognized as self-protection and defense, and is seen in situations such as war where individuals are commanded to act violently by a superior
Out of the eleven books we are using for this research project, three have proven to be extremely helpful in giving us ideas to start our investigation. The first is titled "Aggression in Man and Animals." The book begins with a definition of aggression, which we have discovered is necessary due to the two major types of aggression, and the possibility of variation within the types. A section of this book that is of particular interest to us are the chapters titled "Evolution and Aggression," and "The Developmental Determinants of Aggression," which discuss aggression as a personality trait, as well as culture, family, and child-rearing. The second book is called "Biology, Crime, and Ethics". This book has much useful information done in researching criminal behavior in terms of biology. It goes into much detail about whether or not genetic factors play a role in criminal behavior. The book titled "Origins of Human Behavior" is of particular interest to us because it describes a theory that states that certain people may be more "animalistic" than others, which also affects aggression.
Because we are posing the argument that aggression is a part of human nature, this may lead to the conclusion that little can be changed about it. However, while not denying the natural root of violence, we believe the removal of certain social pressures and situations could possibly reduce the presence of aggression in everyday life. These include: influence of media, smoke, noise pollution, air pollution, abusive parenting, overcrowding, heat, and even atmospheric electricity (Geen, 76). Our project is following in the footsteps of other research on aggression, moving toward similar conclusions, the ultimate desire being to understand why we act violently and if it can be avoided.
To understand human aggression from a biological perspective- scientists study human behavior from its primate origins. They say that aggression has evolved as a behavioral norm in humans because it facilitates survival and adaptation. For example, inter-male fighting may be an adaptive form of aggression because it assures the most desirable spacing of animals within a given territory.
Behaviorists usually tend to treat aggression as a set of acquired behaviors and to attach less emphasis on innate and biological determinants. These scientists commonly apply the "principles of social learning theory" when addressing aggression. Using this approach, aggression is usually dealt with in terms of (1) features of the environment which foster the initial learning or acquisition of the behavior, (2) environmental influences that facilitate the aggressive behavior, and (3) environmental conditions that maintain aggressive behavior.
A number of conditions in the physical environment have proven to elicit aggressive behavior. For instance, the belief that aggression is more likely in hot weather than in cool weather is a common one. One may observe that belief in the Uniform Crime Reports of the FBI which show that peak occurrences of common crimes of violence (such as assault, rape, and murder) occur in the hottest summer months.
The stressful affects of noise have also been well documented. Urban settings are usually characterized by high levels of noise, which can lead to loss of hearing, hypertension, stress, and decreased efficiency in problem solving. The major role of noise in aggression is that it plays the role of an intensifier of ongoing behavior. In other words, if behavior is aggressive, then the introduction of noise facilitates the expression of the aggressive behavior. Noise may also contribute to aggression by reducing an individual's tolerance for frustration.
The scientific consensus concerning the emotion of aggression, along with many other aspects of personality, seems to be that it stems from an individually-defined, hazy combination of genetic makeup and environment. In Biology, Crime, and Ethics, Frank Marsh highlights studies of criminality, all which, "...unanimously reported that parental criminality and offspring criminality seem to be related... between 30 and 45% of offspring with criminal records had one or both parents with criminal records," (Marsh, 67). He goes on to discuss the trend of delinquency and criminality "running in the family," but insists this does not provide support for either a, "...genetic or family environmental causal explanation," (Marsh, 69). Later in the book, Marsh questions whether or not man is innately aggressive. He mentions researchers in the neurosciences, who have isolated the limbic system, the amygdala, the hypothalamus, and the reticular system as parts of the brain from which aggressive behavior stems. Marsh warns of simplifying the "circuitry" of the brain, though, and the danger in saying humans are "wired" for violence, despite their life experience. He summarizes by saying, "...in the generality of human beings, genetic influences alone cannot be responsible for aggressive behavior, in most cases such behavior is largely dependent upon environmental factors," (Marsh, 149). In his book Origins of Human Aggression, Gerald Neuman discusses early forms of man, including Australopithecus, Homo habilis, Homo erectus, Neanderthal Man, and Cro-Magnon Man. He states evidence suggesting that Australopithecus could have been an adept killer, a cannibal, and relied on aggressive skills to survive. He proves that all forms of man could be violent, and that we, as Homo homo sapiens, are no exception. In quoting studies done on monkeys, Frank Marsh states that the capacity for violent behavior was found to be innate, and that the ability to control those aggressive tendencies is what must be learned. Using the quoted research, he again asserts the evidence shows that aggression is, "...an unlearned, innately determined behavior," (Marsh, 152). Further, he groups all aspects of behavior together, saying learning and innate factors both play important roles, in the lives of humans and all animals. Next, the author discusses the influence of genetics. He believes genes do not determine traits, but rather influence the developmental expression of traits, which together, "...represent the expression of the interaction of genes with environments," (Marsh, 153). An individual must learn how to be aggressive. If raised in a violent environment, one may model his life after the examples he was provided, possibly becoming a permanently aggressive person. Marsh makes his final point to summarize, saying,"...the areas of the brain that have become associated with aggressive or violent behavior have been organized by the experience of the individual, and the environments in which he has been socialized, to facilitate the expression of such behavior... The fact is not that man becomes what he is predetermined to become, but that he becomes, as a human being, whatever - within his genetic limitations - he learns to be," (Marsh, 156).

III. Materials and Methods
The following are the survey questions:
1. What is your age?
2. What is your sex?
3. Do you recall any instances of abuse during your childhood?
4. Rate your upbringing on a scale of 1-10, 1 being loving and 10 being violent.
5. Would you consider any family members violent?
6. As a child, were you more intimidated in your own home, or outside of your home?
7. Have you ever been arrested?
8. Have you ever been involved in a physical altercation?
9. Can you recall witnessing violence in your home?
10. ....Outside of your home?
These questions, besides getting a very general idea of the recipient's upbringing, attempt to determine whether their environment or genetic makeup had a greater impact on their personality and any incidents of aggression or violence. For example, in question 8, we ask: As a child, were you more intimidated in your own home or outside of your home? If they answer 'inside,' we can assume they had more immediate exposure to aggression, and their family, who has genetic influence on their behavior, will undoubtedly share some aspects of personality. If they respond 'outside,' we may deduce that their community was at least somewhat threatening some of the time, and that this had an impact on them. In deciding what questions to ask in our survey, we were sensitive to the fact that some of our inquiries could force some recipients to re-live painful memories of abuse or violence during childhood. Therefore, we were careful to ask questions bluntly but simply, and not pry deeply into those issues.
Our survey could have been more unbiased if we had polled a larger, broader group of people. Though we did survey only Miami students, they originally come from a variety of cities all over the United States, and a few select countries. In addition to this, our survey can be trusted because it was anonymous and voluntary, and we carefully reviewed each individual answer while compiling the data.
Our materials were simple and few. We used: library research materials, the internet, writing utensils, over 100 photocopied surveys, data collection sheets, a poster, and peer evaluation.
Timeline:
- February 1, 2000 - Duncan and Lorraine become partners.
- February 3, 2000 - We pick human aggression as our topic and post on the web.- February 15, 2000 - We discuss possible meeting times and poster topics.
- February 21, 2000 - We review all of our research materials, and take notes.
- February 22, 2000 - More background research.
- February 23, 2000 - Compilation of notes form our proposal on the web.
- February 25, 2000 - We pass out over 100 surveys.
- February 28, 2000 - We compile our data and construct our poster.
- February 29, 2000 - We present our poster to the class.
- April 11, 2000 - We submit a progress report to the web.
- April 25 - 2000 - We begin the final version of our project.
- April 27, 2000- Meeting with Hays to learn statview
- April 28, 2000- Graph construction and statview at the peer science center

IV. Results

The graph below shows the data from the fourth survey questions. It reveals that most recipients rated their upbringing as loving, and fewer considered their upbringing violent. This can definitely be attributed to the select group of people we surveyed, Miami students.

V. Discussion and Conclusions

Percentages based on the total number of people surveyed:
- 15% recalled instances of abuse during childhood
- of those who recalled abuse, 69% have been arrested
- of those who did not recall abuse, 13% have been arrested
- 22% of females had been involved in a physical altercation
- 56% of males had been involved in a physical altercation
- of those who had, 24% had been arrested
- of those who had not fought, 12% had been arrested
- 7% of females have been arrested
- 26% of males have been arrested
- 20% consider some family member violent
- 87% of males and 75% of females were more intimidated outside their homes
- 13% of males and 25% of females were more intimidated inside
- 40% of those intimidated inside consider some family member violent
- 14% of those intimidated outside consider some family member violent
- 30% recalled witnessing violence in their home
- 76% recalled violence outside of their home
- 80% who recalled violence in their home also saw it outside
- 75% of those who did not recall violence in their home saw it outside

Our first discovery was that if one recalled abuse during childhood, that person
was more inclined to have been arrested. If one was not abused as a child, they were much less likely to have ever been arrested. Based on this finding, parenting clearly plays a role in the development of aggressive behavior, as 69% of those who were abused were also arrested, compared to only 13% of those who werenít abused. The next finding revealed that males were more likely to be involved in physical altercations (56% of males compared to 22% of females). Males were also proven to be arrested more often than females (26% to 7%). These may seem like expected results, that men fight and have trouble with the law more often, but again point out our biased group of recipients. In a college student population, males are generally more aggressive. Based on our question: do you consider a family member violent, we discovered that 80% of the people surveyed said no, meaning that 80% of the recipients felt that they grew up in a safe environment. This is also likely attributed to the limited group of people we polled. Based on question 8, we deduced that males were more intimidated outside, while women were more intimidated within the home. This could illustrate the presence of domestic violence and abuse toward women within the home, and male aggressiveness outside the home.
Our results generally support what others have done, in that our findings show both genetic and environmental influences play a role in human behavior, specifically aggression. Had we had more time, and didn't feel the pressure of creating a short, concise survey, we could have polled a much broader group of people. In addition to this, we could have delved deeper into how people perceive different kinds of aggression, and exactly what different people consider to be aggressive. What we later discovered, after discussions and library research, is that different groups of people, based on physical location and cultural heritage define aggression differently.

VI. Bibliography
1. Crook, Paul. Darwinism, War, and History. Cambridge University Press. Cambridge.
1994.
2. Ellis, Lee. Crime in Biological, Social, and Moral Contexts. Praeger Press. New
York. 1990.
3. Hennessy, James J. Criminal Behavior. Transaction Publishers. London. 1992.
4. Herrnstein, Richard. Crime and Human Nature. Simon and Schuster. New York.
1985.
5. Jeffery, C.R. Biology and Crime. Sage Publications. Beverly Hills. 1979.
6. Johnson, Roger. Aggression in Man and Animals. WB Saunders Company.
Philadelphia. 1972.
7. Katz, Janet. Biology,Crime, and Ethics. Anderson Publishing Co. Cincinnati. 1985.
8. Raine, Adrian. Psychopathology of Crime. Academic Press. San Diego. 1993.
9. Neuman, Gerard. Origins of Human Aggression. Human Sciences Press. 1987.
10. Whalen, Richard. Neuropsychology of Aggression. Plenum Press. New York.
1974.
11. Wright, Robert. The Moral Animal. Vintage Books. New York. 1994.

Next Article
Previous Article
Return to the Topic Menu

Here is a list of responses that have been posted to this Study...

Respond to this Submission!

IMPORTANT: For each Response, make sure the title of the response is different than previous titles shown above!

Visit the rest of the site!