So what makes somebody a reasonable person, anyway?
Like it or not, there are some requirements to being reasonable. We expect a reasonable person to know certain things, like: fire burns, a loaded gun can go off and if you spill your latte all over someone’s laptop the computer will crash.* You are expected to know anything considered common knowledge in your part of the world (e.g. everybody knows we get flash flood in this area). So bone up on what’s going on around your town because ignorance is not a good excuse once you’re out of the fifth grade.
There are other human conditions which can affect your standing as a reasonable person---like intoxication. Can you be inebriated (by any method you prefer) and still be reasonable? Generally, yes. Although the mythical reasonable person is considered to be a sober person, most courts note that you can be reasonable even though you may be dead drunk.
Intoxication does not automatically make you unreasonable. You can be drunk (or whatever) and still act in a reasonable, sober manner.**
Physical and mental conditions also play a part in determining whether you acted as a reasonable person. For example, if a deaf person walks off the sidewalk because she doesn’t hear the car horn of the oncoming SUV and ends up causing a 20 car pile up, the question is not “what would a reasonable person have done?” But rather, “ what would a reasonable DEAF person have done?”
Or if you suddenly get sick, the question is, "what would the suddenly sick reasonable person do?"
Mental conditions, however, are not treated quite the same way. While it is easy to ask “What would the reasonable blind person do?" It is not so easy to ask “what would the reasonable unreasonable person do?” The jury would probably laugh you out of court. Outside of criminal cases, the insane will be held to the standard of being sane and the mentally challenged will be held to have normal intelligence.
But some thought must be given to people with mental disabilities. The old traditional separations between physical and mental disabilities are being re-examined--especially since many mental disabilities can be traced to physical conditions. Things may be changing, but right now mental or emotional disability will not excuse negligence.
*technically, you can‘t claim ignorance of the danger posed by immersing an electrical appliance in water . The dumping of a latte onto someone’s laptop seems to fall under this general rule.
**reasonableness has nothing to do with DUI arrests. The police usually don’t care how reasonable you are if you fail the breathalyzer test.
For more info: Third Restatement of Torts, Sections 11, 283C, 290