STEPHEN REYSEN is a Professor of Psychology at Texas A&M University-Commerce. His research interests include topics related to personal (e.g., fanship) and social identity (e.g., fandom). Address correspondence to Stephen Reysen at. Stephen.Reysen@tamuc.edu COURTNEY N. PLANTE is an Associate Professor of Psychology at Bishop’s University. His research interests include media effects, the functions of fantasy, fan cultures, and fantasy-themed identities. DANIEL CHADBORN is an Assistant Professor of Psychology at New Mexico Highlands University. His research interests include fanship and fandom, and identity. Popular Culture Studies Journal Volume 10, Issue 1, ©2022 315 Perceived Permeability of Group Boundaries as a Mediator Between Belonging to Multiple Fandoms and Loneliness STEPHEN REYSEN, COURTNEY N. PLANTE, AND DANIEL CHADBORN The term “brony,” a portmanteau of the words “bro” and “pony,” refers to an adult (often male) fan of the television show My Little Pony: Friendship is Magic. The brony fandom is often characterized as unexpected, given its unusual demographic composition for a show that was initially targeted toward preteen girls, and arose through a fortuitous combination of internet culture, nostalgia, and the show’s high production value (Edwards et al.). Despite these unforeseen origins (or perhaps because of them), bronies are especially passionate, loyal both to the show itself and to the fan community which rose up around it for the better part of a decade. In 2019, the show My Little Pony: Friendship is Magic came to an end. In the same year, the largest annual fan convention for the show, BronyCon, announced that 2019 would be its final year. For many fans, the fandom was a social group they felt a greater sense of connection to than even their local neighborhood (Edwards et al.), 2019 was a time of uncertainty for fans, many of whom worried about the fate the brony fandom. Two of the authors, bronies themselves, can personally attest to the bittersweet atmosphere of BronyCon 2019: On the one hand, being at the single-largest gathering of bronies worldwide with an attendance of more than 10,000 while, on the other hand, knowing it would be the last of such gatherings. In many ways, it felt like losing thousands of friends whom one had grown close to over nearly a decade.