Interrelation between Extraversion Level, Neuroticism and Aggressiveness

Aggression is significant problem of modern society. Two main forms of human excessive aggression are described: impulsive and controlled. The first form is seen in patient with depression and is characterized by high emotional reactions and autonomic responses. The second type is revealed in patients with personality disorders and is characterized by low emotional and autonomic responses. We believe that the genetically determined features of neurohumoral status provide the predisposition of organism to impulsive or controlled aggression in humans (to spontaneous and adaptive aggression in animals). In the experiments on animals (submissive and dominant rats) we revealed the dependence of male behavior type on blood plasma testosterone level, tight negative correlation between testosterone level and hypothalamic pituitary adrenal axis hormones, the imbalance between monoamines (noradrenaline, serotonin, dopamine) in frontal cortex, hippocampus, cerebellum. Submissive rats can serve as experimental model of depression. Dominant rats demonstrate adaptive aggression. Before the study of neuro hormonal features in people predisposed to different types of aggression, we decided to investigate the relationship between temperamental characteristics and aggressiveness. The interrelation between extraversion degree, neuroticism level and aggressiveness index was studied in young men. The aggressiveness index was found to depend on both extraversion and neuroticism. According to the obtained results neuroticism does not depend on the degree of extraversion. The aggressiveness index was lower in introverts as compared with both extraverts and persons with middle level of extraversion. The aggressiveness index of extraverts is higher than that of introverts. But difference between aggressiveness index in extraverts and persons with middle level of extraversion was not revealed. Although the correlation between extraversion degree and aggressiveness index was not found, moderated negative statistically significant correlation between the above mentioned parameters was revealed in men with middle level o extraversion. It should be noted that in introverts positive correlation between extraversion degree and aggressiveness index was found. But it is statistically insignificant. The aggressiveness index depended on the neuroticism level. It was lower in persons with low level of neuroticism as compared with persons with both middle and high levels of neuroticism. The aggressiveness index of persons with high level of neuroticism is higher than that of persons with middle level of neuroticism. Middle positive statistically significant correlation was observed between aggressiveness index and level of neuroticism total group of men. It is very interesting, that in introverts and men with middle level of extraversion the correlation between aggressiveness index and level of neuroticism is absent, but it exists in extraverts. So the aggressiveness index depends on the degree of extraversion and level of neuroticism. The aggressiveness index is the highest in men with high level of neuroticism. In extraverts the aggressiveness index positively correlates with neuroticism level and in men with middle level of extraversion the aggressiveness index negatively correlates with extraversion degree.