<p>William Golding’s <i>Lord of the Flies</i> (1954) stands as a canonical text in modern literature, renowned for its profound allegorical depth and bleak diagnosis of inherent human evil. While its philosophical and symbolic dimensions have been extensively explored, its power as a meticulous, sequential case study in group psychology has not been fully systematized within literary criticism. Prevailing scholarship, though rich in symbolic, philosophical, and psychoanalytic interpretation, often overlooks the precise, mechanistic processes of collective psychological disintegration. This paper addresses this critical gap by conducting a sustained and detailed analysis of the novel through the integrated lenses of classical and contemporary group psychology. Moving beyond the foundational theories of Gustave Le Bon and Sigmund Freud’s development, it incorporates modern conceptualizations of the Social Identity Model of Deindividuation, Social Identity Theory, and Social Identity Theory of Leadership. The central thesis of this paper is that the boys’ descent into savagery is not a mere aggregation of individual moral failures, but a predictable, phased process of group formation, polarization, and catastrophic collapse, explicable through established social psychological principles. It systematically examines the initial, tenuous establishment of a rational social order, its systematic usurpation by a primal collective driven by fear, charisma, and altered identity, and the social identity shift. This study concludes that a vigorous group psychological framework provides a systematic, and relevant tool for understanding the mechanics of societal unraveling that Golding depicts, offering critical insights into the perpetual fragility of civilization in the face of collective pressures.</p>