Appreciation test is a legal principle under criminal law. The appreciation test checks the validity of a defense of insanity by requiring proof by clear and convincing evidence of the fact that at the time of a crime, a defendant suffered from a severe mental disease or defect preventing him/her from appreciating the wrongfulness of the conduct. The test, along with a plea of not guilty by reason of insanity was established by the Insanity Defense Reform Act of 1984.
The appreciation test is also used to analyze personality of a person who makes up stories that are assumed to reveal elements of his/her psychological makeup.[United States v. Hill, 750 F. Supp. 524 (N.D. Ga. 1990)]