A last will and testament, along with other important estate planning documents, records a person’s decisions regarding the disposition of their property upon their death. Once you turn 18, you can write and amend your estate planning at any point during your life, so long as you have a “sound mind” at the time you execute the documents.

Like most states, Wisconsin’s laws on the mental capacity required to make and amend estate planning documents find their basis in the English common law. The exact language is found in Wisconsin Statute Section 853.01, which states that “Any person of sound mind 18 years of age or older may make and revoke a will.” While the age requirement is straightforward, the exact requirements of having a “sound mind” are less obvious.

To begin with, it should be noted that the capacity to make estate planning decisions, also known as “testamentary capacity,” is a distinct analysis from other types of capacity related questions. Someone may no longer be capable of living on their own due to mental decline but still may have the capacity to make or amend their estate planning. Even being under the legal guardianship of another does not itself prove the person lacked testamentary capacity.

Unfortunately, a clear and simple test is impossible because mental capacity exists on a multi-dimensional spectrum, while the legal analysis requires a “yes” or “no” answer. Borrowing from the common law tradition, Wisconsin cases have established a three-part test to determine on a case by case basis whether someone was of sound mind at the time of a document’s execution:

(1) The person executing the estate planning documents, also known as the “testator” must understand the nature and extent of his or her estate. This does not require an exact knowledge of investment allocation or dollar signs, but generally the testator should be able to roughly identify what assets they own and about how much they are worth.

(2) The testator must understand who the “natural objects of his or her bounty” are. Unlike some countries, in the United States adult children are not legally entitled to inherit anything from their parents, and subject to a number of limitations, spouses are not legally entitled to inherit from one another either. However, this test requires that at the time the testator made the estate planning decisions, they at least understood which individuals would be expected to receive their estate, usually this means the testator’s spouse or children.

(3) The testator must be able to form a rational conclusion on the selection of beneficiaries and the disposition of the estate. This requirement roughly translates to at least a basic understanding of the facts regarding their family situation and the effect of the estate planning documents. The testator is not required to have a detailed understanding of all of the exact workings of their estate planning documents so long as they basically understand the end-result.

In short, the requirements boil down to: you need to know roughly what you have, who would be expected to receive it and how the estate documents you are signing will affect where things go.

Because the bar for testamentary capacity is somewhat low, applying the three-part test sometimes leads to results where a court finds the testator had a sound mind but where the lay person would probably not think so. A good example of this is the rule for persons suffering from “insane delusions.” If a testator believes all manner of conspiracy theories and holds absurd opinions on matters, but understands their estate, the natural objects of their bounty, and the general effect of the plan they are signing, they likely have proper capacity and a sound mind for estate planning purposes. There is some room for challenge if the insane delusion “materially affected” the disposition because it can be argued the insane delusion impacted their ability to meet the prongs of the test, but even then, these challenges are difficult as courts are usually reluctant to weigh in on whether a belief is “insane” or not. The line between eccentricity and insanity is a difficult one to draw. A now infamous 1947 case is an often-cited cautionary tale of a court extending its analysis past strict legal questions as several male judges weighed in on whether a woman was “insane” for disliking men and giving her fortune to a women’s charity. Needless to say, the case has not aged well.

As an example of an insane delusion “materially affecting” the disposition, consider the following. If a parent disinherited you and also believes aliens have infiltrated our society, then the decision will likely stand if the three factors of the test are met. In contrast, if a parent disinherited you because they believe you are an alien who infiltrated our society, then you may have an argument to challenge the will because the insane delusion affected the ability of the parent to rationally select beneficiaries under the third factor of the test.

The three-factor test is analyzed at the time the document is executed, and it is possible that someone may lack capacity one day and have it the next. It is common for people suffering from certain types of cognitive decline to have good days and bad days. While this type of situation poses certain evidentiary hurdles if a challenge is brought, there is nothing inherently invalid about documents executed during a period where the signor temporarily has a sound mind. This is sometimes referred to as a “lucid period,” and in these situations it is usually wise to take extra care to record the evidence of capacity at the time of document execution. This is especially true if someone in the family is going to be upset with their treatment under the plan, as it increases the odds of a legal challenge.

Even if a testator has a “sound mind” as defined in the three-part test, a will, or portion of a will, may be challenged if an individual exercised “undue influence” over the testator to secure a benefit for themselves. Undue influence is beyond the scope of this article, but generally refers to a situation where someone has improperly applied their influence to get someone to change their estate planning to benefit themselves. One of the requirements for an undue influence claim is that the testator was “vulnerable” to undue influence, usually meaning some level of cognitive impairment, but not to the level of lacking a sound mind for estate planning purposes.

If a testator lacked a sound mind when they created or changed their estate planning directives, then those decisions, in theory, will not be valid or effective at their death. In practice, the technically invalid documents will be submitted to the court, and, if properly executed, will be presumed valid until an interested party to the estate proceedings formally challenges the documents within the required time frame. If no one raises the issue, the court overseeing the estate will have no way of knowing the validity of the presented documents is in question and will likely approve whatever distributions are called for in them. Claims not timely brought are forfeited, as courts have a legitimate interest in bringing all matters relating to an estate to rest within a reasonable amount of time following the death of the individual.

If you have questions or concerns about testamentary capacity or other estate planning topics, you should discuss them with an estate planning attorney.