Muscle tension and personality

Studied the relationship between skeletal muscle activity and personality variables as measured by the MMPI in 17 male and 51 female patients (most with chronic pain) in a large general hospital. After administration of the MMPI, muscle activity was measured from the frontalis. A biserial correlation coefficient was calculated between muscle tension and each of 12 MMPI scales. The high-tension group obtained a significantly higher score on scale L and a significantly lower score on scale PD.