I found a great article on New Scientist the other day by Michael Bond, How Your Friends’ Friend Affect YOur Mood

Here are some excerpts:

“Christakis … found that a person’s happiness is dependent not only on the happiness of an immediate friend but - to a lesser degree - on the happiness of their friend’s friend, and their friend’s friend’s friend. Furthermore, someone’s chances of being happy increase the better connected they are to happy people, and for that matter the better connected their friends and family.”

“Two factors appear crucial: the frequency of social contact, and the strength of the relationship. This is not too surprising: we know that emotional contagion requires physical proximity. It is also likely that the closer we feel to someone, the more empathetic we are towards them, and the more likely we are to catch their emotional state. However, how these two factors play out in day-to-day interactions is uncertain. What is also unclear - because it has never been properly tested - is the extent to which emotions can propagate through virtual networks, where the opportunity for physiological mimicry is much reduced.”

Networks of Influence: New Scientist

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