You can read the abstract on Violent Video Games here…
Scientists now understand that during the stress response an important chemical system becomes activated. Researchers have labeled this system the hypothalamic-pituitary-adrenal axis (HPA axis). When a situation is perceived as stressful, a deep brain structure called the hypothalamus releases a hormone called CRF, which triggers the nearby pituitary gland to release the hormone ACTH.
ACTH then travels through the bloodstream to the adrenal glands located on top of the kidney. The adrenals are then stimulated to release the stress hormones known as corticosteroid and catecholamine. These hormones then initiate the “flight-or-flight” response. By increasing heart rate, blood pressure, and respiration, and organism is ready to either fight or flee from a threatening situation.
In order to understand the role of the hypothalamus in the “fight-or flight” response, one must understand its function in the broader brain structure called the limbic system. The limbic system, which includes the hypothalamus, thalamus, amygdala, and other structures, is not only important for the “fight-or-flight” response. It is also an essential part of the complex circuitry needed for learning, integrating past and present experiences, controlling aggressive behavior, and feeling or expressing emotions. The limbic system receives information from the cerebral cortex, the outer surface of the brain which integrates information about the environment from our senses. On a molecular level, scientists understand that the limbic system is mediated by two neurotransmitters called nor pinephrine and serotonin. Brain stem neurons containing nor epinephrine signal neurons containing serotonin, which then connect to the hypothalamus of the limbic system creating the “fight-or-flight” response. This complex system is therefore in place so that an organism can react when its survival is threatened.
Understanding the stress response if also important, because chronic stress has a detrimental effect on an organism. Chronically elevated corticosteroid levels can precipitate high blood pressure leading to heart disease. Stress hormones can also over stimulate and weaken the immune system, leading to frequent infections and illnesses known as autoimmune diseases. Stress hormones can cross into the brain and shrink the hippocampus, a brain structure important in memory and learning. And lastly, chronic stress deregulates the brain neurotransmitters, leading to illnesses like anxiety and depression.
Now that we understand stress and the complex stress response, we can step back and review the literature on the effects of media violence. We already know by work from Johnson and others that there is a link between violent television exposure and aggression in children and young adults. Bryant has determined that violent television leads to anxiety, mistrust of others, and fear of personal safety. Potter has concluded that women report more frightening reactions to media coverage than men. However, Cantril has suggested that one’s personality determines his reaction to frightening TV content more than any other factor. This personality factor has been called the ”locus of control”, and can be measured by a psychological survey. Locus of control is the term used to describe the extent to which a person feels he is in control of his environment. Those with an external locus of control are more fearful and thus more affected by the media.
They only felt more anxious of becoming a victim of a terrorist attack. Females did react more strongly than males, but more importantly, personality traits such as locus of control had more of an impact on a person’s response to media violence.
In conclusion, Congress and the medical community have had ongoing concerns about the effects of media violence on our society. Research on stress and the stress response reveal than an organism reacts to threatening stimuli with a complex system of neural and hormonal responses. Chronic stress produces damaging effects on multiple body systems. Research on the effects of media violence indicate that some people react with anxiety or aggression. On a molecular level, scientists are still uncovering how neurotransmitters ricochet around the brain and transmit what threats we see with our eyes to what we feel with our emotions We may always be bombarded with violent images in our society, but further studies are still needed to understand its impact on our well being.
The Physical and Psychological Effects of Watching Media Violence
Violence is pervasive in American media. It is estimated that 60% of television material contains violent images and information. Studies have determined that during their school years children witness 180,000 TV murders, rapes, assaults, and armed robberies. Concerns about the negative effects of prolonged exposure to violent media prompted the U.S. Surgeon General and the American Medical Association to conclude that violent television has an adverse effect on society and causes aggression in children. There have even been congressional hearings to legislate what is appropriate material to be viewed by TV and film audiences. But what exactly are the physical and psychological effects of media violence on an individual? What studies have been done and can these effects be measured?
To begin to understand the effects of media violence, one must understand the concept of stress. Stress, as defined by engineers, describes how forces put a strain on an object. In 1936, Hans Selye adopted the term stress to describe the impact of various “noxious agents” on a biological organism. Selye believed that many different factors can put strain on an organism leading to the same phenomenon of stress. In addition, the term stress response refers to the series of neurological and hormonal events that affect the brain and body.
During the 1960’s, John Mason studied the stress response by measuring stress levels when patients were subjected to various stressors. Mason determined that the stress response was more likely triggered by situations that were perceived as novel or unpredictable. Other studies have revealed that the most important factor in determining a stress reaction was the individual’s sense of control over the situation. This would explain why studies have show that up to 30% of elderly people have higher levels of stress hormones. For this population, coping with chronic illness, loss of loved ones, and lack of sense of control increases stress.
I hypothesize that women have a stronger psychological and physical stress response to violence than men, but that after repeated exposure, that responses of both groups will lessen as they become desensitized to repeated viewing of violence.
Electronic blood pressure and heart rate monitor
Watch with a second hand for measuring respiratory rate
Clips from the following 3 movies: “Jaws”, “Swordfish”, and “Psycho”
TV with DVD player
Pencil and paper to record data
Graph paper and markers
Locus of Control survey
- . Practice using an electronic blood pressure monitor until proficient with it.
- Pick sections from 3 movies that show 3 minutes of violence.
- Recruit 9 healthy adult males and 9 healthy adult females who are not on any medication, because many medicines can affect a person’s stress response and vital signs.
- Ask each person to fill out a locus of control survey, as this may be a confounding variable. Locus of control measures how much control a person feels they have over their life.
- Record each person’s age and gender. Also, record how often they watch media violence as this may be a confounding variable in the study.
- Record each person’s resting blood pressure, heart rate, and respiratory rate.
- When showing the 3 movie clips, people should watch the movie clips in different order. This will help determine if they really become desensitized to violence during the experiment, instead of reacting more or less to one particular movie that is always shown last.
- Show the movie clip.
- At the end of the clip, measure blood pressure, heart rate, and respiratory rate. Repeat this every few minutes until the vital signs return to their resting measurements. Vital signs will return to normal in about 20 minutes.
- To make sure you are measuring a stress response to violence, record if each person felt fear during the clip and how violent they thought the movie was on a scale of 1 to 10. Also, record if they have seen the clip before, as this can be a confounding variable.
- Repeat steps 7 to 9 for each of the 3 movie clips.
Data and Analysis
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In reviewing the data, I determined that the groups of men and women were similar in age and measure of locus of control. Specifically, the mean age for men was 45 compared to 43 for women. The locus of control score was 109.4 for men compared to 108.2 for women. This made these groups similar enough to safely be compared on the basis of gender. The groups did differ however, on how much violence they viewed in their daily lives.
For example, 78% or men watched violence some of the time, while 22% of men watched violence frequently. This compared to 56% of women who watched violence some of the time, while 22% watched violence frequently. The remaining 11% of women never watched violence. Because the two groups differed on the frequency of violence viewed, it may be a confounding variable and needed to be evaluated later in the study.
The first question I needed to address, was if the subjects thought that they were actually witnessing violence. This is important to make sure we are actually measuring a response to watching violence. Women scored a mean of 7.7 out of 10 on the violence intensity scale compared to men, who scored somewhat lower with a mean of 6.4. This would indicate that women viewed the clips as somewhat more violent than men did.
Once I determined that the subjects believed the clips were violent, I then addressed the question of whether the subjects felt fear from viewing these clips. This is important because fear is required to initiate the stress response. Results showed that 93% of women felt some degree of fear from the films compared to only 44% or men. Given that fear is the emotion driving the physical stress response, gender differences would probably come to predict that that women also would have a stronger physical stress response to the movies than men.
Next, I determined which physical vital sign (systolic blood pressure, heart rate, or respiratory rate) was the best indicator of a person’s response to violence. The data revealed that the most sensitive indicator of the stress response to violence was an increase in respiratory rate, followed by heart rate, and then systolic blood pressure. Both genders reacted with this same pattern whether they had seen the movie before or not. However, many more women responded with changes in all vital signs compared to men, showing that women were much more physically reactive to the films.
There are three possible confounding variables in this study that may affect desensitization to violence that needed to be addressed. Firstly, the issue of locus of control was evaluated. When the LOC score was plotted against the heart rate measurement, there was no correlation. This would indicate that locus of control was not a confounding variable in the experiment (graph in log book).
Secondly, given that men and women watch violence to different degrees in their lives, this could also be a confounding variable in the study. I then compared the degree of physical response to the films as compared to how often a person watched violence in their daily life. What the data revealed was that while men’s heart rate increased slightly (0.5-0.9), women’s heart rate increased more in response to the films the more they watched violence in their own lives (1.9-4.7).
Thirdly, the experimental results could also be confounded by whether the subject had seen the clip before, and this variable also needed to be assessed. The same pattern appeared when comparing the physical change in heart rate to whether a person had seen the movie before. Specifically, while the percentage of men who physically reacted to the films declined if the were familiar with the movie (57% to 30%), the percentage of women reacting to the clip increased if they already seen the film (75% to 91%). This would indicate that women may be more and more physically reactive by witnessing frequent or familiar media violence.
Lastly, I evaluated whether subjects actually became desensitized to violence as they watched successive movies during the experiment. The results again revealed differences between men and women. For example, with each successive movie, men’s systolic blood pressure and heart rate declined below baseline, indicating that they actually became relaxed while viewing more and more violence.
In terms of respiration, men experienced an increase in respiratory rate, which then declined with successive violence. In contrast, women showed a different pattern. Women’s systolic blood pressure declined with successive violence, but still remained above their baseline systolic blood pressure. As for heart rate and respiratory rate, women showed a persistently elevated change from baseline, revealing physical evidence that women may become affected with successive exposure to violence.
My hypothesis was only partly true. Men and women did respond differently to media violence in several ways. On a psychological level, women reported more fear than men. However, when experiencing fear, both groups responded in the same physical way. Respiratory rate, heart rate, and systolic blood pressure all responded as part of the stress response for both groups. However, in agreement with my hypothesis, far more women responded with each physical response than men in the study.
In addition, my hypothesis about desensitization was also only partly true. When watching violence in their own lives, men who watched frequent violence experienced less fear and change in heart rate during the experiment compared to men who only watched some violence. Thus, men appeared somewhat desensitized to violence exposure in their lives. However, women who watched frequent violence experienced more fear and heart rate changes compared to women who only watched some violence. Therefore, men became desensitized to violence exposure while women did not.
This was confirmed in the experiment itself in two other ways. Firstly, men who were familiar with the films physically responded less than men who had never seen the films, indicating that they became physically desensitized to violence that was familiar. Women however, were not desensitized and physically responded more strongly to a film if they had previously seen it. Secondly, men seemed to physically relax with successive exposure to violence, because heart rate and systolic blood pressure fell below their resting levels during the course of watching the 3 films. Women however, became more reactive rather than desensitized to the violence during the study.
To improve on the experimental design and yield stronger results, future studies should look at larger numbers of subjects and longer exposure times to violent media. In addition, personal knowledge of statistics would help me to better analyze my data. Variations on the experiment could be useful to find out if these gender differences hold true for teenagers and children. Additionally, other media could be tested, such as violent news coverage, video games, and rap music.
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We live near Chicago and crime is up, so the media tells use. Just listening to the news is a violent experience! That is why Super Science Fair Projects like this one are so important for kids to do because it heightens their awareness and they become more sensitive to the effects.