Indignation - Physiology

Physiology

The external expression of anger can be found in facial expressions, body language, physiological responses, and at times in public acts of aggression. The facial expression and body language are as follows: The facial and skeletal musculature are strongly affected by anger. The face becomes flushed, and the brow muscles move inward and downward, fixing a hard stare on the target. The nostrils flare, and the jaw tends toward clenching. This is an innate pattern of facial expression that can be observed in toddlers. Tension in the skeletal musculature, including raising of the arms and adopting a squared-off stance, are preparatory actions for attack and defense. The muscle tension provides a sense of strength and self-assurance. An impulse to strike out accompanies this subjective feeling of potency.

Physiological responses to anger include an increase in the heart rate, preparing the person to move, and increase of the blood flow to the hands, preparing them to strike. Perspiration increases (particularly when the anger is intense). A common metaphor for the physiological aspect of anger is that of a hot fluid in a container. According to Novaco, "Autonomic arousal is primarily engaged through adrenomedullary and adrenocortical hormonal activity. The secretion by the adrenal medulla of the catecholamines, epinephrine, and norepinephrine, and by the adrenal cortex of glucocorticoids provides a sympathetic system effect that mobilizes the body for immediate action (e.g. the release of glucose, stored in the liver and muscles as glycogen). In anger, the catecholamine activation is more strongly norepinephrine than epinephrine (the reverse being the case for fear). The adrenocortical effects, which have longer duration than the adrenomedullary ones, are modiated by secretions of the pituitary gland, which also influences testosterone levels. The pituitary-adrenocortical and pituitary-gonadal systems are thought to affect readiness or potentiation for anger responding.

Neuroscience has shown that emotions are generated by multiple structures in the brain. The rapid, minimal, and evaluative processing of the emotional significance of the sensory data is done when the data passes through the amygdala in its travel from the sensory organs along certain neural pathways towards the limbic forebrain. Emotion caused by discrimination of stimulus features, thoughts, or memories however occurs when its information is relayed from the thalamus to the neocortex. Based on some statistical analysis, some scholars have suggested that the tendency for anger may be genetic. Distinguishing between genetic and environmental factors however requires further research and actual measurement of specific genes and environments.