This book examines how digital platforms are reconfiguring the parameters of agency and reflexivity in contemporary social life. Drawing on Margaret Archer's social realist framework, it moves beyond treating platforms merely as tools or environments to conceptualize them as distinct sociotechnical structures with emergent properties and powers that shape human action without determining it. The book develops the concept of platform and agency to explore the temporal dimensions of sociotechnical change, tracing how platforms condition personal and collective reflexivity through mechanisms of distraction, cultural abundance, and multiplying communication channels. While affirming the analytical distinction between structure, culture and agency, it demonstrates how platforms constitute a fourth dimension necessary for understanding contemporary social morphogenesis. Through the conceptual pairing of psychobiography and personal morphogenesis, the book offers a nuanced account of how individuals become who they are within platformized lifeworlds. Rather than announcing an epochal break with previous social forms, the analysis illuminates the accumulating consequences of platform mediation across biographical timescales. This book will interest researchers and graduate students in social theory, philosophy of technology, digital sociology, platform studies, media and communication studies, critical data studies, internet studies, surveillance studies, sociology of knowledge, digital anthropology, and social informatics.
