This paper investigates the correlation between group identity mentions and expressions of ingroup solidarity and outgroup hostility in social media posts and engagement (shares, likes, reactions) on Ukrainian social media before and after the 2022 Russian invasion. Using a dataset of 1.6 million posts from Ukrainian news sources on Facebook and Twitter, and a geolocated sample of 149,000 Ukrainian tweets, the study reveals that before the invasion, outgroup mentions were strongly associated with engagement. Post-invasion, ingroup solidarity posts showed a stronger association with engagement than outgroup hostility, a pattern consistent across both news and non-news sources. The findings suggest that signaling ingroup solidarity online is associated with higher engagement during intense intergroup conflicts.

Yara Kyrychenko, Tymofii Brik, Sander van der Linden, Jon Roozenbeek