Testamentary incapacity, undue influence, and insane delusions are recurring doctrines in the context of an impaired, weakened, or confused individual leaving a will, the validity of which comes under question. In In re Estate of Berg (SD 2010), the South Dakota Supreme Court held that an individual possessed testamentary capacity even where he suffered a static lifelong delusion about the identity of his father and was unable to articulate an accurate estimate of his net worth. The author offers an analysis of the holdings and outcome in Berg along with related cases and authority in context.
Simmons, Thomas E, Testamentary Incapacity, Undue Influence and Insane Delusions (October 1, 2015). South Dakota Law Review, Vol 60, No 2, 2015.