The categorical test is a legal standard for determining whether there has been adequate provocation to reduce a murder charge to voluntary manslaughter. Traditionally, the mens rea for murder was malice aforethought. While murder and voluntary manslaughter are both intentional homicides, adequate provocation mitigates a defendant's culpability. Adequate provocation is a legal requirement for a murder charge to be reduced to voluntary manslaughter. The test for adequate provocation varies across jurisdictions and has changed over time. The categorical approach is based on common law principles, but most courts today apply less restrictive tests, such as the extreme emotional disturbance test in Model Penal Code jurisdictions.