Emotional contagion

It is well known that stress states such as fear, panic, and hysteria are socially communicable.

However, it is turning out that other mental illnesses have a component of social contagion implicated in their genesis as well. For example, the following articles deal with the contagiousness of depression and loneliness.

• Is Depression Contagious?
• Depression and Loneliness Are More Contagious Than You Think
• Depression Is Contagious: How the Most Common Mood Disorder Is Spreading Around the World and How to Stop It
• Could Depression Actually Be a Form of Infectious Disease?

Emotional contagion may be a widespread phenomenon. Of course, social contagion alone doesn't prove that memes are implicated. Manipulation by transmissible DNA-based pathogens is also a possibility. However memes are surely the number one suspects in such cases.

A significant study that illustrates social contagion of emotions was recently conducted by Facebook. Such social networking studies have the potential to distinguish meme-based contagion from gene-based contagion - because they can filter out short-distance relationships, leaving long-distance ones - where only meme-based social contagion is likely.

Emotional contagion seems important to understand - because of the extent of its social significance. For example, many organizations would probably prefer to manipulate their workers into states conducive to a positive working environment - and not have them too depressed or stressed.