This study examines the impact of social media on family bonds in the Global South, with a particular focus on Bangladesh. Building on Putnam’s ‘bowling alone’ thesis, the research reframes social fragmentation in collectivist contexts as a process unfolding primarily within households rather than civic institutions. Employing a sequential explanatory mixed-methods design, the study combines a nationally stratified household survey (n = 1,200) with in-depth interviews and family focus group discussions.Quantitative findings reveal a significant negative association between intensive social media use and family cohesion, mediated in part by reduced shared family time. Passive social media consumption is found to be more corrosive to family interaction than active, relational use. Qualitative evidence contextualizes these patterns, highlighting mechanisms such as attentional displacement, erosion of everyday family rituals, emotional withdrawal, and gendered burdens of emotional labor. Generational differences further reveal a normalization of fragmented interaction among youth, alongside parental concern over declining intimacy.The study contributes theoretically by extending social capital theory to the digital era in the Global South, emphasizing the vulnerability of bonding social capital under algorithmic attention economies. Policy implications underscore the need for family-centered digital literacy, education-based interventions, and platform accountability frameworks that prioritize relational well-being. By centering family life as a critical site of digital impact, this research advances a human-centered perspective on digital transformation in Bangladesh and comparable contexts.