Breach is the second element of negligence, and it asks whether the defendant's conduct fell below the standard of care. The measure is the reasonable person under the circumstances. That person is a legal construct, not an average person, and the test is objective: the defendant's own good intentions, poor judgment or lack of experience do not lower the bar. Circumstances are taken into account, but the defendant's personal shortcomings mostly are not.
Rule
- The standard. Reasonable care in the circumstances, judged objectively.
- The Hand formula. Failing to take a precaution is unreasonable where the burden of the precaution is less than the probability of harm multiplied by the severity of that harm.
- Physical and mental traits. A physical disability is part of the circumstances. Low intelligence, inexperience and a bad temper are not.
- Children. Judged against a child of similar age, intelligence and experience, unless engaged in an adult and inherently dangerous activity.
- Professionals. Held to the knowledge and skill of a reasonable member of the profession, proved by expert testimony.
- Custom and statute. Industry custom is evidence but not conclusive. Violation of a safety statute can be negligence per se where the plaintiff is in the protected class and the harm is the type the statute guards against.
Leading cases
- Vaughan v. Menlove: a defendant who stacked a hayrick badly could not defend on the ground that he had used his own best judgment.
- United States v. Carroll Towing Co.: Judge Hand set out the burden, probability and loss comparison that has framed breach analysis ever since.
- The T. J. Hooper: tugs without radios were negligent even though the industry had not adopted them, because an entire industry can lag behind reasonable care.
Where students go wrong
The first error is writing a conclusion instead of an analysis. Saying the defendant was clearly careless earns almost nothing. Tie each fact to the burden, the probability and the severity, and the points appear.
The second is treating custom as decisive. Compliance with industry practice is evidence of reasonable care, and departure from it is evidence of the opposite, but neither settles the question.
The third is forgetting that negligence per se still needs causation and damages. A statutory violation supplies the standard, not the whole claim.
FAQ
Is the reasonable person an average person?
No. The reasonable person is a standard of ordinary prudence, which may be more careful than the average person actually is.
How is a professional judged differently?
By the customary skill and knowledge of the profession, usually established through an expert witness, rather than by lay common sense.
Does breaking a statute automatically mean liability?
No. Negligence per se establishes breach where the plaintiff is within the class the statute protects and the harm is the kind it aimed at. Causation and damages still have to be proved.
Related terms
Working through this in your own casebook takes longer than reading it here. Syllume starts from your syllabus and turns each assigned case into a brief you can study from.