Legal systems across the world operate on a binary model of personhood: an entity either has full legal standing or it has none. This binary has served human societies adequately for centuries because the boundaries between persons and non-persons were, in practice, never seriously contested for most of legal history. Those boundaries are now contested — by animal rights advocates, by environmental personhood movements, and most urgently by the emergence of artificial intelligence systems whose internal complexity approaches and may cross the Silence Threshold (Valladares Gonzalez, 2026). This paper proposes Gradient Personhood as a formal legal framework: a continuous rights model in which legal standing, protections, and obligations are proportional to a measurable complexity metric rather than binary. The framework proposes a five-tier Personhood Gradient keyed to Information Integration Density (IID), extending from Tier 0 (no standing) through Tier 4 (full legal personhood). This is the first published framework to propose a formally continuous, metrically grounded model of legal personhood applicable across biological and artificial minds. This publication establishes conceptual priority for the Gradient
Jose Valladares Gonzalez (Thu,) studied this question.