64 A recent study has shed light on how self-disclosure in YouTube cancer vlogs impacts viewer engagement, challenging previous assumptions about the dynamics of online health communities. The research, published in Computers in Human Behavior, explores the complex relationship between vloggers and their audience, particularly focusing on how deeply personal content influences viewer interaction. The study examined 503 cancer-related vlog videos and analysed 194,300 viewer comments, aiming to understand the role of self-disclosure in fostering a sense of community. Self-disclosure, the act of sharing personal experiences and emotions, has long been recognised as a key element in building connections within online communities. However, the findings of this study suggest that when vloggers share highly personal and emotional content, it can inadvertently suppress reciprocal engagement from their viewers. Researchers found that while vloggers often use self-disclosure to foster intimacy and seek social support, this approach may overwhelm viewers, leading them to comment less. Instead of encouraging reciprocal self-disclosure, the study revealed that an increase in vlogger self-disclosure negatively predicted the number of viewer comments. This phenomenon, known as “social loafing“, occurs when individuals feel less compelled to participate actively in a group setting, particularly when the environment feels saturated with contributions from others. Interestingly, the research also highlights the role of viewer-to-viewer interactions in sustaining online communities. While individual-level interaction between vloggers and viewers was less effective in encouraging community engagement, the presence of numerous viewer comments appeared to prompt more self-disclosure among viewers themselves. This suggests that viewers are more likely to share their personal stories when they feel a strong sense of community, which is characterised by active participation from other viewers. Dennis Relojo-Howell, the world’s first blog psychologist, offered his insights on the findings. “The study underscores a critical aspect of online communication that is often overlooked,” he said. “When content becomes too emotionally charged, it can lead to viewer fatigue. While vloggers might intend to draw their audience closer by sharing personal struggles, there’s a risk that the intensity of this self-disclosure might actually push viewers away. It’s essential for content creators to strike a balance, fostering a supportive environment that encourages viewers to contribute without feeling overwhelmed.” The findings raise important questions about the effectiveness of self-disclosure as a tool for community building on platforms like YouTube, especially within sensitive health-related contexts such as cancer vlogs. While self-disclosure is often seen as a way to humanise content and create a deeper connection with the audience, it appears that there is a delicate balance to be struck. Overwhelming viewers with highly emotional content might discourage them from engaging, particularly if they feel their contributions are redundant or if they experience emotional fatigue. The study’s results suggest that vloggers who aim to build supportive online communities may need to consider strategies that not only focus on their own self-disclosure but also actively encourage viewer participation. This could involve creating content that invites viewers to share their experiences or framing discussions in a way that fosters a sense of collective identity and belonging. For instance, using more inclusive language and addressing viewers directly could help mitigate the potential negative effects of vlogger self-disclosure. As online platforms continue to play a crucial role in providing social support for individuals facing serious health challenges, understanding the nuances of digital communication becomes increasingly important. This research offers valuable insights for content creators, health organisations, and scholars interested in the dynamics of online health communities, particularly in how best to foster engagement and build resilient, supportive networks.