Do the offline and social media big five have the same dimensional structure, mean levels, and predictive validity of social media outcomes?

Prior studies found that the Big Five personality traits are significant predictors of social media outcomes, but they did not specify the situational context of the Big Five. The assumption is that people have the same personality on social media as offline. The present research addressed whether the Big Five are the same on social media as offline in terms of dimensional structure, mean levels, and predictive validity of social media outcomes. Across two samples, 943 college students completed measures of social media outcomes and two versions of the Big Five Inventory-2 adapted from Soto and John (2017), specifying offline and social media contexts. Findings revealed that all of the five dimensions emerged in both contexts, except that a few items might not apply well to the social media context. The mean levels of all five traits were significantly different between contexts, suggesting that the dimensional structure of the offline and social media Big Five are similar but peoples' levels of expression of the Big Five are not the same between these contexts. Conscientiousness and extraversion were the least similar dimensions out of the five between the contexts. There were also differences in predictive validity between the offline and social media Big Five showing that heavier social media users are more open, conscientious, and extraverted on social media, whereas they are lower on these traits offline. Consequently, studying offline and social media contexts separately and jointly is critical for understanding how the Big Five predict social media outcomes.