Learning Outcomes
After reading this article, you will understand how the law of negligence treats physically and mentally impaired individuals. You will be able to apply the correct standard of care, distinguish between physical and mental impairments, and answer MBE-style questions about foreseeability, liability, and common exam traps related to this subtopic.
MBE Syllabus
For the MBE, you are required to understand how physical and mental impairments affect the standard of care in negligence. This article covers:
- The reasonable person standard as applied to individuals with physical disabilities.
- The treatment of mental impairments and insanity in negligence law.
- The foreseeability of harm and liability for actions caused by impaired individuals.
- The difference between physical and mental impairments for exam purposes.
- How intoxication and sudden incapacity are analyzed under the MBE.
Test Your Knowledge
Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.
-
Which standard of care applies to a defendant with a physical disability in a negligence action?
- The standard of a reasonable person with the same disability
- The standard of a reasonable person without the disability
- Strict liability
- The subjective standard of the defendant's actual abilities
-
How does the law generally treat mental illness or insanity in determining negligence liability?
- It excuses the defendant from liability
- It is treated the same as a physical disability
- It is not considered and the defendant is held to the ordinary reasonable person standard
- It results in strict liability
-
Which of the following is most likely to be a defense to negligence for a sudden loss of consciousness?
- Voluntary intoxication
- Foreseeable epileptic seizure
- Unforeseeable heart attack
- Chronic mental illness
Introduction
Negligence law uses the reasonable person standard to assess whether a defendant breached a duty of care. When a defendant is physically or mentally impaired, the law must decide whether to adjust this standard. This article explains how the MBE tests the standard of care for physically and mentally impaired individuals, and how courts determine liability when impairment contributes to harm.
The Reasonable Person Standard and Physical Disabilities
The reasonable person standard is objective. For individuals with a physical disability, the law compares their conduct to that of a hypothetical reasonable person with the same disability, not to a person without it.
Key Term: Reasonable Person Standard The objective legal standard used to judge conduct in negligence cases, based on how a typical person with ordinary prudence would act in similar circumstances.
Key Term: Physical Disability A bodily impairment that limits a person's physical abilities, such as blindness, deafness, or loss of limb, and is considered when setting the standard of care in negligence.
A person who is blind, for example, is expected to act as a reasonable blind person would. The law recognizes that physical limitations affect what is reasonable, but still expects reasonable precautions in light of the disability.
Mental Impairments and the Standard of Care
Mental impairments, including mental illness, insanity, or cognitive disorders, are treated differently from physical disabilities. The law generally does not adjust the standard of care for mental impairments. A defendant is held to the same standard as a reasonable person without regard to mental incapacity.
Key Term: Mental Impairment A condition affecting a person's mind or cognitive function, such as insanity or mental illness, which does not alter the standard of care in negligence law.
The rationale is that mental incapacity is often difficult to detect, may pose risks to others, and should not excuse negligent conduct. The only exception is where the impairment is sudden and entirely unforeseeable (see below).
Sudden Incapacity and Foreseeability
If a defendant suffers a sudden, unforeseeable physical or mental incapacity—such as an unexpected heart attack or seizure—the law may excuse liability if the incapacity was not reasonably foreseeable.
Key Term: Sudden Incapacity An abrupt loss of physical or mental function that could not have been anticipated or prevented, potentially excusing negligence if truly unforeseeable.
If, however, the defendant knew or should have known about the risk (e.g., a history of seizures), liability is likely.
Intoxication
Voluntary intoxication is not treated as a disability. An intoxicated person is held to the same standard as a sober reasonable person. Intoxication does not excuse negligence.
Children with Disabilities
Children are generally held to the standard of a reasonable child of similar age, intelligence, and experience. If a child has a physical disability, the standard is adjusted accordingly. Mental impairments are not usually considered.
Worked Example 1.1
A defendant with a prosthetic leg trips and causes another person to fall. In a negligence action, what standard applies?
Answer: The defendant is compared to a reasonable person with a prosthetic leg. If the defendant took reasonable precautions given the disability, there is no breach.
Worked Example 1.2
A driver with a long history of epileptic seizures has a seizure while driving, loses control, and injures a pedestrian. Is the driver liable?
Answer: Yes. Because the driver knew of the risk, the seizure was foreseeable. The driver is held to the standard of a reasonable person with epilepsy, including taking precautions such as not driving.
Worked Example 1.3
A person with schizophrenia, during a psychotic episode, negligently causes a fire. Is mental illness a defense?
Answer: No. Mental illness or insanity does not excuse negligence. The defendant is held to the ordinary reasonable person standard.
Exam Warning
The MBE often tests the distinction between physical and mental impairments. Do not confuse the two. Physical disabilities adjust the standard of care; mental impairments do not.
Revision Tip
If the impairment is physical and permanent, adjust the standard. If it is mental or due to voluntary intoxication, apply the ordinary reasonable person standard.
Key Point Checklist
This article has covered the following key knowledge points:
- The reasonable person standard is objective but adjusts for physical disabilities.
- Mental impairments do not change the standard of care; defendants are held to the ordinary standard.
- Sudden, unforeseeable incapacity may excuse negligence if truly unpredictable.
- Voluntary intoxication is not a defense to negligence.
- Children with physical disabilities are compared to reasonable children with similar disabilities.
- The MBE frequently tests the difference between physical and mental impairments.
Key Terms and Concepts
- Reasonable Person Standard
- Physical Disability
- Mental Impairment
- Sudden Incapacity
