We all have that friend. Let's call her Jane. Jane is bubbly and gregarious. Jane doesn't attend a party, she manifests it. She seeks out social gatherings and is enlivened by human presence. Jane is a good listener and has many trusted friends. What can explain Jane's extroversion? The answer, astonishingly, is her attraction to human body odor.
Think of the last time you visited a restaurant. How was the service? Was the waiter or waitress smiling? Could you pick up on their mood? Now think carefully. At the end, was the amount of gratuity offered influenced by how he/she made you feel? Of course it was. “Service with a smile” is a social contagion phenomenon similar to “Monkey See, Monkey Do,” whereby the emotional relevant stimuli is mimicked among members during a face-to-face interaction. What hasn’t been tested yet is whether this event holds true among social networks. Until now.