Experimental evidence of massive-scale emotional contagion through social networks
Proceedings of the National Academy of Sciences of the United States of America (2014) - Comments
pubmed: 24889601  doi: 10.1073/pnas.1320040111  issn: 1091-6490  issn: 0027-8424 

Adam D. I. Kramer, Jamie E. Guillory, Jeffrey T. Hancock