Relationship between sympathovagal tone and personality traits

This study evaluates the relationship between an individualʹs autonomic tone and his prominent personality traits. Parasympathetic tone was assessed by the high frequency component of heart rate variability, sympathetic tone was assessed by the pre-ejection period which was derived from the impedance cardiogram. 51 subjects participated in the study who were free of any clinically relevant psychological or physical disorder. Subgroups of subjects were formed showing either a high or a low level of sympathetic and parasympathetic tone respectively. A wide range of personality traits was evaluated by using well-known psychometric questionnaires. Results of two-factor ANOVAs revealed substantial differences in personality characteristics depending on the level of sympathetic and parasympathetic tone respectively. There were, however, no significant interaction effects. Correlational analysis showed remarkable relationships between sympathetic tone and some prominent personality traits. By introducing one of these personality traits (anxiety) as a covariate into two-factor ANCOVAs the originally obtained results were markedly altered.