Respiratory sinus arrhythmia is associated with trait positive affect and positive emotional expressivity.

The associations among respiratory sinus arrhythmia (RSA), trait positive affect and positive emotional expressivity were investigated in the present study. Physiological data were collected from 98 college students during baseline and fear film-viewing and recovery periods in the lab, and their affectivity data were collected three times (immediately before, 4 months after and 12 months after the physiological data collection) using the Positive and Negative Affect Schedule (PANAS) and Emotional Expressivity Scale. The results showed that trait positive affect was stably associated with baseline RSA independently of trait negative affect. Positive emotional expressivity was also stably associated with baseline RSA independently of negative emotional expressivity. Neither trait affect nor emotional expressivity was associated with RSA reactivity or RSA rebound. These findings suggest that baseline vagal tone might be the parasympathetic correlate of individuals with a positive emotional style.