Missing Works Cited
In the article “Stress and Aggression reinforce Each Other at the Biological Level, Creating a Vicious Cycle”, by Menno Kruk, the author demonstrates how there is a direct correlation between stress and violence not only in rats but humans as well. IN an attempt to break the cycle of violence in humans they began with rats and it was discovered that the answer may lie within the nervous system. There appears to be a fast, mutual, positive feedback loop between stress hormones and a brain-based aggression-control center in rats, whose neurophysiology is similar to ours (Kruk 1).
Several experiments have been done in an attempt to break the cycle of violence in rats, which then can be used to help break the cycle of violence in humans. In five experiments using rats, neuroscientists studied the affect of stimulating the brains aggression mechanism to see if the blood levels of corticosteroid were elevated simultaneously. The results showed a direct correlation between stress and aggression in rats, which usually were not aggressive by nature. Normally rats only respond aggressively when they are in a fight or flight situation. Menno Kruk says, “It is well known that these stress hormones, in part by mobilizing energy reserves, prepare the physiology of the body to fight of flee during stress. Now it appears that the very same hormones ‘talk back’ to the brain in order to facilitate fighting”.
In order for scientists to study their hypothesis of another feedback loop, they removed the rats’ adrenal glands to prevent the release of corticosterone. Researchers then injected the rats with corticosterone. Within minutes, the hormone facilitated stimulation-evoked attack behavior. (Kruk 1). The rats became aggressive even when there were no other rats or any form of a threat around. This reaction showed that stimulating the hypothalamic attack area in rats led to elevated stress hormones and higher stress hormones led to aggression. This showed that aggression and stress go hand and hand and that the two factors actually feed each other and keeps the cycle of violence going.
The resulting cycle would explain why aggressive behavior escalates so easily and is so difficult to stop once it has started, especially because corticosteroids rapidly pass through the blood-brain barrier. The research suggests that even when stress hormones spike for reasons other that fighting, they lower the attack threshold enough...