Shared identity and shared information in social media: development and validation of the identity bubble reinforcement scale

Social media facilitates the formation of identity bubbles that reinforce shared identities, social homophily, and reliance on the information shared within the bubbles. Currently, researchers need more social psychological measures to assess how people perceive their relationships with online networks and information shared on social media. This article reports the development and Finnish and English validations of the identity bubble reinforcement scale (IBRS), consisting of subscales on social identification, homophily, and information bias. Studies 1 and 2 (N = 1200, N = 160; age 15–25 years) validated the 6-item measure (IBRS-6) in Finland and Study 3 replicated the results with both 6-item and 9-item (IBRS-9) measures in the United States (N = 501, age 18–25 years). Across all 3 studies and 2 countries, the IBRS showed good construct validity and correlated positively with social media use and group-behavior measures. The IBRS is an applicable measure for social media group behavior, and its subscales can also be used separately.