The notion of something going viral online is nothing new. But there’s a fast expanding area of study in social media and how we share things — the study of Mass Psychogenic Illness on the Internet. Incidents of socially spreading hysteria and other forms of illness go back hundreds of years, but new technologies could be making these incidents spread faster and farther.

Karen North, professor of social media and psychology at the University of Southern California, joins Marketplace host Ben Johnson to discuss. 

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