Authors: Johannes C Eichstaedt; Hansen Andrew Schwartz; Margaret L Kern; Gregory Park; Darwin R Labarthe; Raina M Merchant; Sneha Jha; Megha Agrawal; Lukasz A Dziurzynski; Maarten Sap; Christopher Weeg; Emily E Larson; Lyle H Ungar; Martin E P Seligman Journal: Psychol Sci Date: 2015-01-20