Modeling Dynamics of Cultural Exploration on Reddit

The question of how people explore online spaces, such as blogs, forums and social media platforms, is of fundamental importance in understanding how information and cultural norms spread. Examining the interplay between the structure of these spaces, the individual, and the overall community provides valuable insights into the mechanisms governing population mobility over digital and conceptual spaces. Given the relatively young age of this field, research has so far been limited to analyzing mobility over short time periods. In this study, our goal is to identify the key processes that shape the dynamics of a population consistently active in an online space over an extended period. We focus on a population active on Reddit for nearly ten years, analyzing their attention and exploration patterns—respectively, the entropy of their visited subreddit distribution, and the growth rate of the number of known subreddits over time—and the temporal variation of these patterns at both individual and global scales. Our findings reveal that global exploration, activity, and attention rates all decline over time, indicating that users distribute their attention more evenly across topics of interest, but simultaneously explore and interact less. We then develop several models based on key parameters defined at the individual level to try to replicate the global population dynamics. This allows us to identify the key social and attitudinal factors influencing user behavior. Specifically, we propose a model that combines a user's intrinsic interest in specific topics with a tendency to follow trends, which successfully replicates the population's attention patterns. Exploration patterns, on the other hand, are captured by a model that balances users' discovery of new topics with their inclination to return to familiar ones. Our results demonstrate that it is possible to capture key features of population dynamics over long periods. Moreover, these dynamics can be reproduced by integrating individual attitudinal traits with the general social tendency to follow the behavior of the broader population.