Anger spurs surprising changes in body

When a person gets angry, it is often possible to see them physically tense up, but now researchers have found out that anger also decreases stress hormones.

Inducing emotions generates profound changes in the autonomous nervous system, which controls the cardiovascular response, and also in the endocrine system, affecting hormone levels. In addition, changes in the activity of the brain also occur, especially in the frontal and temporal lobes. With regard to asymmetrical frontal brain activity and emotion, there are two models - the first model, 'of emotional valence', suggests that the left frontal region of the brain is involved in experiencing positive emotions, whilst the right is more related to negative emotions. The second model, 'of motivational direction', suggests that the left frontal region is involved in experiencing emotions related to closeness, whilst the right is associated with the emotions that provoke withdrawal. Positive emotions, like happiness, are usually associated to a motivation of closeness, and the negative ones, like fear and sadness, are characterised by a motivation of withdrawal. However, not all emotions behave in accordance with this connection.

Previous research has shown an increase in heart rate and blood pressure when anger is experienced. Increased testosterone and decreased cortisol in response to anger and aggressive behavior have also been reported. To analyse  other biochemical reactions that occur in a person's body when they are angry, right down to the cellular level, and  changes in brain asymmetry, researchers made 30 men angry through the use of 50 first-person phrases known to provoke the emotion. The researchers then measured the men's biochemical activity before and after they became upset.

Anger not only boosted the heart rate, made arteries tense up and increased the production of the hormone testosterone, it actually caused levels of the stress hormone cortisol to fall. It was also found that anger tends to stimulate the left hemisphere of the brain, the side associated with positive emotions related to closeness. Increased activity in that part of the brain generally results in a desire for closeness rather than the withdrawal triggered by negative emotions. The researchers explain that the case of anger is unique because it is experienced as negative but, often, it evokes a motivation of closeness. In other words, normally when we get angry we show a natural tendency to get closer to what made us angry to try to eliminate it.

The findings of this unique study are along the same lines as previous investigations and defend what has been noted by Darwin that the emotions, in this case anger, are accompanied by unique and specific (psychobiological) patterns for each emotion.