The Biological Bases of Anger
Currently, very little is known about the biological and physiological aspects of anger that differentiate it from other emotions such as fear, anxiety, and elation. There is, however, a large amount of information available on the causes of emotions in general, and it will be necessary to discuss the generalities of emotions in order to relate the operative concepts that concern anger. Many of the theories on emotional origins conflict with each other - this site will discuss a few of the major theories.
Emotions are complex in their origins and in their effects. In their most minute form, emotions appear to be nothing more than physiological responses to external stimuli. Some researchers believe that emotions are dependant on biological causes alone. Others maintain that human emotions are the product of many factors, and that biochemistry alone cannot explain the mysteries of anger. Several schools of emotion theory exist. Here are a few of the most important.
The causes of anger are thought to be very similar to those of many other emotions, ranging from elation to fear. In times of emergency, the sympathetic nervous system is activated. This is the portion of the body's peripheral nervous system that increases blood flow, heart rate, and adrenaline output. Adrenaline, also known as epinephrine, is a hormone released by the adrenal glands that stimulates many of the physiological activities that characterize stress-induced emotions.
On this page, you may have noticed the red-based graphics. In our society, anger is often associated with the color red because of the red flush that people often get when angry. This flush is caused by increased blood flow to the blood vessels in the face, which is caused by the increase in epinephrine.
For some people, the physical effects of excess anger can be dangerous. Blood flow is increased in the body's blood vessels by constrictions in the arteries. When arteries contract, blood flows faster and is reoxygenated more quickly, but blood pressure rises and the heart must pump harder and faster. In individuals with a previous history of heart disease, this sudden increase in blood pressure in the coronary arteries can contribute to future heart disease, and may in extreme circumstances contribute to a heart attack or stroke.