Effects of Opinion Climate, Efficacy Messages, and Publicness of Social Media on Intentions to Retransmit Anti-Binge Drinking Messages on Facebook.

Reducing the rate of college binge drinking is a major public health goal. Social media sites such as Facebook serve as platforms for young adults' online communication, so they could potentially extend the reach of health campaign messages via retransmission. Thus, it is important to identify the factors that predict intentions to share health-related messages on social media. Drawing on the Spiral of Silence framework, the current research examined the effects of opinion climate, message efficacy, and publicness of social media on message retransmission intentions for anti-binge drinking "how-to" messages-messages that include advice and recommendations that target beliefs about efficacy. A 2 × 2 × 2 (efficacy: high vs. low × opinion climate: support vs. oppose × channel: public vs. private) between-subjects experiment was conducted. Data from 245 participants on Amazon Mechanical Turk demonstrated that people were more willing to share when they had an anti- rather than a pro-binge drinking opinion climate, when the messages were more useful, and when they were asked to share via private messaging rather than via public status updates. Theoretical and practical implications for the psychological mechanisms underlying message retransmission on social media are discussed.