As AI systems are increasingly incorporated into domains where human behavior has set the norm, a challenge for AI governance and AI alignment research is to regulate their behavior in a way that is useful and constructive for society. One way to answer this question is to ask: how do we govern the human behavior that the models are emulating? The American legal system's answer lies in the `Reasonable Person Standard,' an idea that comes up in nearly every area of law and forms the basis for how we evaluate human behavior. The legal system often judges the actions of parties with respect to what a reasonable person would have done under similar circumstances. We argue that the reasonable person standard provides useful guidelines for the type of behavior we should develop, probe, and stress-test in models. We explain how the reasonable person standard is defined and used in key areas of the law using illustrative cases. As we do so, we also discuss how the reasonable person standard could apply to AI behavior in each of these areas and contexts, and how it can be a useful technical goal for AI researchers.