  Narratives can be powerful tools for inspiring action on pressing societal
issues such as climate change. While social science theories offer frameworks
for understanding the narratives that arise within collective movements, these
are rarely applied to the vast data available from social media platforms,
which play a significant role in shaping public opinion and mobilizing
collective action. This gap in the empirical evaluation of online narratives
limits our understanding of their relationship with public response. In this
study, we focus on plant-based diets as a form of pro-environmental action and
employ natural language processing to operationalize a theoretical framework of
moral narratives specific to the vegan movement. We apply this framework to
narratives found in YouTube videos promoting environmental initiatives such as
Veganuary, Meatless March, and No Meat May. Our analysis reveals that several
narrative types, as defined by the theory, are empirically present in the data.
To identify narratives with the potential to elicit positive public engagement,
we used text processing to estimate the proportion of comments supporting
collective action across narrative types. Video narratives advocating social
fight, whether through protest or through efforts to convert others to the
cause, are associated with a stronger sense of collective action in the
respective comments. These narrative types also demonstrate increased semantic
coherence and alignment between the message and public response, markers
typically associated with successful collective action. Our work offers new
insights into the complex factors that influence the emergence of collective
action, thereby informing the development of effective communication strategies
within social movements.
