Facial expressions and personality: a kinematical investigation during an emotion induction experiment.

BACKGROUND/AIMS In order to elucidate the relationship between personality traits and expression of positive emotions in healthy volunteers, standardized personality inventories and kinematical analysis of facial expressions can be helpful and were applied in the present study. METHODS Markers fixed at distinct points of the face emitting ultrasonic signals at high frequency gave a direct measure of facial movements with high spatial-temporal resolution. Forty-six healthy participants (mean age: 40.7 years; 20 males, 26 females) watching a witty movie ("Mr. Bean") were investigated. RESULTS Speed of "laughing" was associated with higher scores on Zuckerman's Sensation Seeking Scale and NEO-FFI (Openness to Experience). CONCLUSION Kinematical analysis of facial expressions seems to reflect sensation seeking and related personality styles. Higher speed of facial movements in sensation seekers suggests lowered serotonergic function.