Scientists from the University of Valencia who studied the physical effects of anger have found that when we get angry, the heart rate, arterial tension and testosterone production increases, cortisol (the stress hormone) decreases, and the left hemisphere of the brain becomes more stimulated.
“Inducing emotions generates profound changes in the autonomous nervous system, which controls the cardiovascular response, and also in the endocrine system. In addition, changes in cerebral activity also occur, especially in the frontal and temporal lobes,” Neus Herrero, main author of the study and researcher at UV, said.
The researchers induced anger in 30 men using the “Anger Induction” (AI) test, consisting of 50 phrases reflecting daily situations that provoke anger. Before and immediately after the inducement of anger the team measured the heart rate and arterial tension, the levels of testosterone and cortisol, and the asymmetric activation of the brain (using the dichotic listening technique), the general state of mind and the subjective experience of anger.
The results, published in the journal Hormones and Behavior, reveal that anger provokes profound changes in the state of mind of the subjects (“they felt angered and had a more negative state of mind”) and in different psychobiological parameters. There is an increase in heart rate, arterial tension and testosterone, but the cortisol level decreases.
Nonetheless, “by focusing on the asymmetric brain activity of the frontal lobe that occurs when we experience emotions, there are two models that contradict the case of anger,” the researchers said.
The first model, ‘of emotional valence,’ suggests that the left frontal region of the brain is involved in experiencing positive emotions, while the right is more related to negative emotions.
The second model, ‘of motivational direction,’ shows that the left frontal region is involved in experiencing emotions related to closeness, while the right is associated with the emotions that provoke withdrawal.
Positive emotions (e.g., happiness) usually are associated with closeness; the negative ones (e.g., fear and sadness) are characterized by withdrawal.
However, not all emotions behave accordingly. Anger in particular can be experienced as negative but provoke closeness.
“When experiencing anger, we have observed in our study an increase in right ear advantage, that indicates a greater activation of the left hemisphere, which supports the model of motivational direction,” Herrero points out. In other words, when we get angry, our asymmetric cerebral response is measured by the motivation of closeness to the stimulus that causes us to be angry and not so much by the fact we consider this stimulus as negative: “Normally when we get angry we show a natural tendency to get closer to what made us angry to try to eliminate it,” he said.