Why emotions are so contagious      

• We're quick to read other people 
• We use verbal and non-verbal cues like...
• ...facial expressions, tone of voice, posture and physical movements  
• These cues explain their emotional state 
• Ex. A 😡 is perceived as anger 
• The problem - we automatically begin to mimic what we see and hear!
• Once we mimic, we "catch" the emotion 😷
• Negative emotions are more contagious 😖 

(SOURCE: K. Hatfield, 2014, co-author Emotional Contagion and a professor of psychology at the University of Hawaii)