Social network site use, mobile personal talk and social capital among teenagers

•Mobile personal talk has a positive relationship with network capital among teens.•SNS adoption and mobile personal talk jointly predict teens’ civic participation.•Different SNS activities have different relationships with social capital.•Mobile talk moderates relationships between various SNS activities and social capital.

Social network sites (SNSs) and mobile phones are becoming increasingly important in teenagers’ lives. Using data collected from a nationally representative survey (N = 800), this study explores the variation of social capital by SNS adoption, different SNS activities, and mobile personal talk among teenagers. The results indicate that SNS adoption and mobile personal talk can not only enhance teenagers’ close ties with friends, but also jointly promote teenagers’ civic engagement. Among SNS users, mobile personal talk also increase teens’ network capital. Different SNS activities such as commenting on friend’s Facebook pictures and joining Facebook groups have different relationships with social capital, and such relationships are moderated by mobile personal talk.