Also known as: incapacities to consent · incapacitated to consent · incapacity for consent · lack of capacity to consent · incompetence to consent
Written by attorneys · grounded in primary & secondary sources — see below
A condition in which a person lacks the mental capacity to understand the nature and consequences of an act. Any apparent consent given by such a person is legally ineffective for purposes of intentional invasions of interests of personality.
Mr. Lang, an elderly patient with advanced dementia, sat confused in a hospital emergency room. Nurse Perez jokingly slapped his hand to demonstrate an IV site, leaving a bruise. Lang replied weakly, "okay, I guess," but his cognitive impairment prevented him from grasping the nature of the contact. Because Lang lacked capacity to consent, the apparent agreement provided no defense to battery.
A female complainant agreed to intercourse after a male defendant impersonated her boyfriend. The court examined whether the complainant could consent under the statute defining lack of consent. Because the complainant was mentally defective, she lacked capacity to consent, rendering any apparent agreement ineffective and supporting the charge.
Select any source to read its text and confirm it supports the definition.
A person lacks capacity when mental disability or impairment prevents understanding the nature and consequences of the conduct. Advanced dementia, recent concussion with disorientation, or court-appointed guardianship for decision-making each demonstrate such incapacity.
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No. A weak verbal reply does not create effective consent if the speaker cannot appreciate the nature of the contact. Courts focus on objective evidence of impairment rather than superficial words of agreement.
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A court-appointed guardian for personal decisions supplies strong evidence of incapacity. Nonverbal cues such as smiles or clapping cannot overcome that finding when policies require verbal consent or guardian approval for close contact.
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Yes. A concussion sustained two days earlier that produces delayed responses and a dazed appearance undermines the ability to understand proposed physical contact, rendering any nod or lack of objection ineffective.
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…common law. [^maj-17]: Recognizing that the statutory rape law stemmed from traditional notions underlying the presumption of incapacity to consent, presuming that the male was responsible for the occurrence and the female was "too innocent and naive to understand the implications and nature of her act", in Hernandez, 61 Cal.2d at…