Fenne Grosse Deters, a psychology researcher at the Free University Berlin, and Matthias Mehl recruited about 100 undergraduates at the University of Arizona. All participants filled out initial surveys to measure their levels of loneliness, happiness and depression, and they gave the researchers access to their Facebook profiles by friending a dummy user.

The researchers found that just writing a status update might help the participants feel more connected. Facebook users have a target audience in mind when they are writing an update. By doing this, they  are thinking about their friends. This has a possible “social snacking” effect as result: “Similar to a snack temporarily reducing hunger until the next meal, social snacking may help tolerate the lack of ‘real’ social interaction for a certain amount of time,”

Abstract of the research paper:

Online social networking is a pervasive but empirically understudied phenomenon. Strong public opinions on its consequences exist but are backed up by little empirical evidence and almost no causally conclusive, experimental research. The current study tested the psychological effects of posting status updates on Facebook using an experimental design. For 1 week, participants in the experimental condition were asked to post more than they usually do, whereas participants in the control condition received no instructions. Participants added a lab “Research Profile” as a Facebook friend allowing for the objective documentation of protocol compliance, participants’ status updates, and friends’ responses. Results revealed (1) that the experimentally induced increase in status updating activity reduced loneliness, (2) that the decrease in loneliness was due to participants feeling more connected to their friends on a daily basis, and (3) that the effect of posting on loneliness was independent of direct social feedback (i.e., responses) by friends.