Communication Anxiety:
The Physiological Responses

The classic account of the physiological effects of anxiety or “stress” on the body is Walter Cannon’s famous “fight or flight” formulation; that is, when an organism is faced with threat, instinctive bodily changes take place which prepare that organism for fighting or fleeing from the perceived danger (1927). According to this theory, all organisms are naturally in a condition of “homeostasis”—or balance—between the external environment and the internal workings of the body.

Now, in Cannon’s view, acute stress is an event (e.g. illness, athletic competition, physical confrontation, delivering a speech, etc.) that disturbs one or more elements of the bodies’ internal milieu. Simply put, the body encounters a stressor and immediately begins to change or adapt its internal processes to deal with the external event. Initially, the body responds by involving its “vaso-regulatory system and its neural and endocrine connections”, otherwise known as the autonomic nervous system. This system is called “autonomic” because it is not subject to direct conscious control (although it may be altered or modified somewhat by certain techniques including deep breathing, progressive muscle relaxation, imagery, etc.).

The autonomic system consists of two parts: the parasympathetic part which “stimulates digestive, vegetative, and other up-building functions” of the body; and the sympathetic part which is the “medium for accelerating heartbeat, raising blood pressure, realizing adrenaline into the blood, and other phases of mobilizing the energies of the organism into fighting or fleeing from danger” (May, 1977, 59). Once this system is aroused the bodies’ stress response moves into the acute or “alarm phase” when there is a catecholamine surge from the adrenal medulla portion of the brain.

“The effect of this surge is to increase heart rate and output; increase peripheral vascular resistance; inhibition of vegetative functions such as digestion; increased arousal, reflexes, aggression, and anxiety; increased mobilization of energy stores (increased glucose, increased fatty acids released into the bloodstream), and inhibition of water excretion—or a voiding of one’s bladder and bowels. In addition, acute stress causes a sudden surge in cortisol, growth hormone, and prolaction”---the prolonged presence of which may lead to various diseases such as peptic ulcers, asthma, hypertension, and diabetes.

The above-mentioned bodily changes have probably been experienced, to a greater or lesser degree, by anyone who has ever found him or herself in a public speaking situation. Before going up to the podium a speaker may notice that her heartbeat has accelerated considerably—this is so that more blood may be pumped into the muscles, which will be needed in what the body anticipates to be a struggle. In addition, the blood vessels in the bodies’ periphery constrict so as to maintain arterial pressure for the upcoming emergency or crisis. This causes a loss of skin color (e.g. one becomes “white” with fear) and gives the skin a cold, clammy feel. Breathing may become deeper and more rapid in order to ensure a plentiful supply of oxygen—in extreme cases, this may cause hyperventilation. The pupils of the eyes dilate so that a better view of the oncoming danger might be had; hence, the common expression “eyes wide with fear”. The liver increases its output of glucose into the bloodstream so that the body has plenty of immediate energy to draw upon—this may produce a jittery or “shaky” feeling. One might also break out into a “cold sweat”, a process which the body initiates so that it may cool itself down before the exertion of the impending struggle. A substance is released into the blood that allows it to clog quickly in case of bleeding or bodily trauma. Furthermore, all “vegetative functions” or digestive activity is suspended so that blood may be moved away from the stomach to the muscles. With this, the speaker is likely to experience a loss of appetite before, during, and after delivering her speech. Just before delivering the speech, the speaker may feel an urge to urinate or defecate—the body wishes to “void” itself to be more ready for strenuous activity. Finally, while speaking it is common to experience a dry mouth due to a “decrease in the flow of saliva corresponding to the suspension of the flow of gastric juices in the stomach” (May, 60). With all of this going on inside of one, it is certainly no wonder why so many people consider public speaking to be an unpleasant experience!

Now that the biological underpinnings of speech anxiety have been outlined, the question naturally arises: why is it that some people seem to be able to handle the stressor of public speaking much better than others? The answer lies, as we shall see, in some combination of natural traits, or heredity, learning, and conditioning. To begin with, it is the case that not all stressors are equal; there are unconditional and conditional stressors. Stressors that act directly to alter an organism’s homeostatis are labeled “unconditional stressors”. These sorts of stressors are independent of setting or situation, and largely independent of an organism’s conditioning or learning. An example of an unconditional stressor is a direct physical assault, e.g. an armed robbery. Basically all people physically react in the same way to an unconditional stressor. A “conditional stressor”, on the other hand, is mostly by itself a “biologically insignificant stimuli”. Conditional stressors become significant through a “process of association and learning”. Thus, people often react differently when confronted with conditional stressors. Public speaking is a good example of a conditional stressor. Speaking in front of others, taken in and of itself, poses no physical danger or biological threat. Nevertheless, public speaking is stressful for many people, and indeed, elicits a significant physiological response. Others, however, because of their individual upbringing, learning, personal experience, or biological genetic “stock”, do not experience the stressor of public speaking in the same way or degree.