Making friends on Facebook: Common group membership as a central decision rule

Abstract The present study examines the role of group identification and common group membership as a decision rule when accepting friendship requests on Facebook from unknown users. To look for motives regarding social capital increase, a methodically triangulated approach was chosen, combining qualitative methods (focus groups) and quantitative data in form of a description of the sample group (questionnaire). Because social desirability biases were expected during the data collection, a qualitative experiment was designed beforehand, giving the opportunity to ask people why they have done something and not how they would react under certain circumstances. A confederate created a fake profile (including average information, incognito pictures and some expectable noise on the profile page) into two online groups on Facebook. These groups are intended for students of a university in Eastern Germany (n = 119) and our confederate sent out friendship requests to 102 of those members, from which 84 were accepted. Subsequent focus group discussions and a quantitative questionnaire showed that common ground, especially common group membership, is a central decision rule for accepting friendship requests from unknown people. The matter of context is discussed when dealing with online phenomena like building social relationships and, of course, the ethical implications for the online experiment and the unavoidably deceitful process.