I Learned It By Watching You

Have you ever felt like others’ negative moods are contagious? If you feel a connection to them, you may be right. Participants who were led to feel a connection to a confederate based on shared interests (e.g., favorite movies, music, travel destinations) felt more stress when the confederate exhibited greater stress and anxiety while preparing for a speech. Similarly, participants experienced increased heart rate and blood pressure when watching the confederate engage in strenuous exercise. 

Cwir, D., Carr, P. B., Walton, G. M., & Spencer, S. J. (2011). Your heart makes my heart move: Cues of social connectedness cause shared emotions and physiological states among strangers. Journal of Experimental Social Psychology, 47(3), 661-664.