What standard is used to judge breach of duty in negligence cases?

The reasonable man standard is the benchmark used to determine whether a defendant has breached their duty of care in negligence cases. This standard reflects the actions that a hypothetical average person would take in similar circumstances. It is based on an objective measure, which does not depend on the individual characteristics or intentions of the defendant but rather on the conduct expected from a reasonably prudent person.

This approach allows courts to assess whether the defendant's behavior fell below that which society would generally expect, promoting fairness and consistency in legal outcomes. If the defendant's actions are deemed not to meet this standard—meaning a reasonable person would have acted differently—then a breach of duty is established.

In contrast, other options do not serve as valid measures for determining breach of duty. The subjective judgment of the claimant might reflect personal beliefs or feelings which are not universally applicable and can lead to inconsistencies. Judgment by legal experts would introduce bias based on individual expert opinions rather than a standardized approach. Historical practices in negligence could vary widely and may not be relevant to current societal expectations. Thus, the reasonable man standard remains the optimal and most widely accepted criterion in evaluating negligence cases.