Alison C. White, Amie Zarling
ABSTRACT Guided by Ecological Systems theory, this article examines how the manosphere—a network of antifeminist online communities—functions as a developmental context shaping boys' and young men's masculinity development. Drawing on research about adolescence, digital socialization, and masculinity, we argue that algorithm‐driven digital platforms such as TikTok, YouTube, and Instagram now operate alongside families, peers, and schools as powerful microsystems of gender socialization. We outline how manosphere content becomes appealing and effective through three mechanisms (e.g., affect, homosociality, and algorithms) and trace its presence across ecological systems from proximal influences to broader ideological forces such as patriarchy and neoliberal individualism. We then consider implications for identity development, emotional regulation, family dynamics, and gendered harms experienced by girls and women. Viewing the manosphere as a risky developmental environment, we call for human development and family scholars and practitioners to more fully integrate digital ecosystems into research, prevention, and intervention efforts.