Decomposing Matrilineal-to-Patrilineal Transitions: Cross-Cultural Stress Tests of Succession, Localization, and Descent

Matrilineal-to-patrilineal change is often treated as a single institutional transition, although inheritance, residence, corporate descent, political succession, and intergroup relationships can change at different times. We treat these as separable institutional margins and apply a preregistered measurement discipline to ask what standard cross-cultural data can actually adjudicate. The motivating mechanistic hypothesis is that repeated high-stakes cooperation among men from different maternal descent groups may create action-validated, partner-specific relational capital; where preserving such relationships increasingly favors father–son continuity and male local retention, horizontal cross-matriline coalitions may contribute to pressure toward paternal organization. The SCCS/D-PLACE variables used here do not directly observe that core relational mechanism. We therefore preregister two downstream stress tests using Standard Cross-Cultural Sample data. A succession-by-localization interaction was non-adjudicable when succession was measured directly because of sparse cells, and an upstream productive-sex-bias proxy showed no positive interaction with localization across raw, regional, temporal, or genealogical-control analyses. A second preregistered test confirmed descriptive residence–descent dissociation but did not support the predicted localization-selective effect. These results do not test the coalition-origin mechanism directly. They instead support a narrower contribution: descent transitions should be decomposed into separately measured institutional margins, coarse explanatory proxies should not be mistaken for the latent relational mechanism, and preregistered null results can delimit what the available measurement layer can establish. Direct relational, historical, and archaeogenomic designs are required for the motivating mechanism itself.