In an effort to provide a better understanding for what testamentary capacity expert psychologists look for when forming opinions about whether the person had testamentary capacity in the execution of a will, trust, beneficiary designation, or other testamentary contractual document, I am highlighting the statutes, case law, and jury instructions specific to all 50 states. Each will be in its own blog post. Thirteenth up, Illinois.

Beyers v. Billingsley, 369 N.E.2d 1320 (Ill. App. Ct. 1977), 369 N.E.2d 1320

Testamentary capacity requires sufficient mental ability to (1) know and remember who are the natural objects of his bounty, to (2) comprehend the kind and character of his property and to (3) make disposition of the property according to some plan formed in his mind (citing Quellmalz v. First National Bank (1959), 16 Ill.2d 546, 158 N.E.2d 591; Morecraft v. Felgenhauer (1931), 346 Ill. 415, 178 N.E. 877.).

Deliberate disinheritance of an heir does not establish inability to know the natural objects of testator’s bounty. (citing Ennis v. Illinois State Bank of Quincy (1969), 111 Ill. App.2d 71, 248 N.E.2d 534.).

It has also been stated that if a person has sufficient mental capacity to transact ordinary business and act rationally in the ordinary affairs of life, he has sufficient mental capacity to dispose of his property by will (citing Shevlin v. Jackson (1955), 5 Ill.2d 43, 124 N.E.2d 895; Quellmalz v. First National Bank (1959), 16 Ill.2d 546, 158 N.E.2d 591.).

In re: Bonjean’s Estate, 90 Ill.App.3d 582, N.E.2d 205, 45 Ill.Dec. 872 (3d Dist. 1980)

An “insane delusion” is present where a testator, without evidence of any kind, imagines or conceives something to exist which does not exist in fact, and which no rational person would, in the absence of evidence, believe to exist.

An insane delusion may render a will invalid if it can be shown that the will was a product of, or influenced by, the delusion. The insane delusion must affect the will or enter into its execution. Even if the testator has an insane delusion on a particular subject, and the property is disposed of according to a plan, the will will not be set aside for lack of testamentary capacity.

Ryan v. Deneen, 375 Ill. 452, 457, 31 N.E.2d 582, 584 (1940)

Unkind or unjust remarks indicating a prejudice against the natural objects of the testator’s bounty do not show he suffered from insane delusions.

Roller v. Kurtz, 6 Ill. 2d at 628, 129 N.E.2d at 697 (1955)

A mental disturbance, therefore, may or may not reach the state where one loses his capacity to make a valid will; and a failure to recognize someone, and an unreasonable prejudice against the natural objects of one's bounty, do not necessarily indicate a failure of mental power.

Illinois Civil Jury Instructions § 200.10 Testamentary Capacity—Personal Characteristics of Decedent

If you believe that Decedent had insane delusions at the time he executed the document purporting to be his last will, you may consider this together with all the other evidence in determining whether Decedent had the mental capacity to make a will.