Recently, the #FreeBritney saga cast a harsh spotlight on state guardianship systems. Yet despite their serious flaws, guardianship regimes have benefited from waves of reform. Indeed, since the 1970s, most jurisdictions have taken steps to protect the autonomy of people with cognitive, intellectual, or developmental disabilities (CIDD). Likewise, lawmakers are currently experimenting with supported decision-making (SDM): an alternative to guardianship designed to help individuals with CIDD make their own choices. These changes are no panacea, but they have modernized a field that once summarily denied “idiots” and “lunatics” power over their affairs.
However, in a related context, the legal system’s treatment of individuals with CIDD remains rooted in the past. Since the sixteenth century, judges have voided wills executed by owners who lack testamentary capacity. This Article reveals that this notoriously problematic rule has resisted the progressive forces that have swept through guardianship law. The Article then offers fresh insight into how parties litigate testamentary capacity claims by reporting the results of a study of 3,449 estates from California. Finally, the Article analyzes several unsettled doctrinal issues, such as whether testators have due process rights to participate in adjudications of their own competence, the relationship between SDM and will-making, and the appropriate capacity test for nonprobate transfers.