Both research and public debates around social media use tend to involve a premise of positivity bias, which refers to presenting one’s life in an overly positive light by various different means. This premise contributes to multiple potentially important follow-up hypotheses, such as the fear of missing out and low self-image effects, due to repeated consumption of positive social media content (e.g., Bayer et al. 2020, for a review). The positivity bias of social media use, itself, has received limited research attention. 
 
In the present study, Masciantonio and colleagues (2025) tested positivity bias in the context of three social media platforms: Facebook, Instagram, and X. The experiment involved recruiting participants (n=312) into platform-specific user groups and crafting posts to be shared with friends as well as respective social media audiences. For social media positivity bias to differ from everyday positivity bias, posts in the former should introduce more positive valence in comparison to offline sharing—and if the platforms differ in their encouragement of positivity bias, they should introduce significant between-platform differences in valence.
 
Based on how the participants reported events, the study found no significant differences between everyday and social media positivity bias, but messages posted on Twitter/X had a more negative valence than posts in other social media platforms. The results would be consistent with the implication that people's positive actions in social media simply follow the natural human tendency to present oneself positively to others—a hypothesis that should be investigated in follow-up work. More research attention should also be given to specific design features, which may contribute to platform-specific differences in user habits, as suggested by the distinct valence rate found in relation to Twitter/X.

 

The Stage 2 manuscript was evaluated by three experts (areas: experimental methods, social media, statistics) via in-depth peer review across two rounds, with one reviewer returning to validate analysis code and methdological accuracy on a final round. Based on the authors’ careful responses and revisions, the revised manuscript was judged to meet the Stage 2 criteria and was awarded a positive recommendation. 

 
URL to the preregistered Stage 1 protocol: https://osf.io/9z6hm
 
Level of bias control achieved: Level 6. No part of the data or evidence that was used to answer the research question was generated until after IPA.  
 
List of eligible PCI RR-friendly journals:

 

 

 
1. Bayer, J. B., Triệu, P., & Ellison, N. B. (2020). Social media elements, ecologies, and effects. Annual review of psychology, 71, 471-497. https:// doi.org/10.1146/annurev-psych-010419-050944

 

2. Masciantonio, A., Heiser, N., & Cherbonnier, A. (2025). Unveiling the Positivity Bias on Social Media: A Registered Experimental Study On Facebook, Instagram, And X [Stage 2]. Acceptance of Version 2 by Peer Community in Registered Reports. https://osf.io/s93yu 

Both research and public debates around social media use tend to involve a premise of positivity bias, which refers to presenting one’s life in an overly positive light by various different means. This premise contributes to multiple potentially important follow-up hypotheses, such as the fear of missing out and low self-image effects, due to repeated consumption of positive social media content (e.g., Bayer et al. 2020, for a review). The positivity bias of social media use, itself, has received limited research attention, however. 
 
In the present study, Masciantonio and colleagues (2024) will test positivity bias in the context of three social media platforms: Facebook, Instagram, and X. The experiment involves recruiting participants into platform-specific user groups and crafting posts to be shared with friends as well as respective social media audiences. If positivity bias manifests in this context, the social media posts should introduce more positive valence in comparison to offline sharing—and if the platforms differ in their encouragement of positivity bias, they should introduce significant between-platform differences in valence.
 
The Stage 1 plan was reviewed by four independent experts representing relevant areas of methodological and topic expertise. Three reviewers proceeded throughout three rounds of review, after which the study was considered having met all Stage 1 criteria and the recommender granted in-principle acceptance. 
 
URL to the preregistered Stage 1 protocol: https://osf.io/9z6hm
 
Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA.  
 
List of eligible PCI RR-friendly journals:

 

 

 
1. Bayer, J. B., Triệu, P., & Ellison, N. B. (2020). Social media elements, ecologies, and effects. Annual review of psychology, 71, 471-497. https:// doi.org/10.1146/annurev-psych-010419-050944

 

2. Masciantonio, A., Heiser, N., & Cherbonnier, A. (2024). Unveiling the Positivity Bias on Social Media: A Registered Experimental Study On Facebook, Instagram, And X. In principle acceptance of Version 4 by Peer Community in Registered Reports. https://osf.io/9z6hm