Why does negligence law usually not consider a defendant's lack of experience or intelligence?

In the context of tort law, the doctrine of negligence relies on an external standard of behavior rather than the subjective characteristics of an individual. Because the law aims to protect society against unreasonable risk, it evaluates conduct based on the hypothetical "reasonable person"—an objective benchmark used to determine whether a defendant’s actions were careless.12

Consequently, the law generally examines only the conduct itself, disregarding factors such as a defendant's personal ignorance, stupidity, or lack of experience. By utilizing this objective criteria, courts can maintain a consistent standard of care that adjusts for the magnitude of potential injury and the likelihood of harm, rather than attempting to measure the internal mental state or individual capabilities of every defendant. While the law may make limited allowances for certain physical disabilities, it does not typically account for mental deficiencies or lack of experience, as doing so would undermine the protective purpose of the negligence standard.12