Analyze and then discuss why the reasonable standard of care differs for different categories of individuals. Is there any logic on which to base these differences because of societal need and expectations? Does justice demand a different result? Why would the courts make these distinctions?

The courts have not been merely arbitrary in coming to the distinctions. The distinctions are based on what a reasonable person can expect from such individuals, what usually occurs in the majority of situations, justice, and the perennial fear the courts have of being flooded by cases that have no solution.
a. Children vary in their capabilities, responsibilities, and what their parents will allow them to do. Third parties dealing with children who may be negligent deserve some protection. However, minor children cannot be held to the same standards as adults. Generally, the third person is aware of dealing with a child and can respond accordingly. In the case of a child performing an adult activity, a third person's expectation can understandably be that the child should behave as an adult would.
b. People who deal with others with physical disabilities are generally put on notice by the physical appearance of the disabled person that they are indeed dealing with someone whose physical capabilities will be different from those who are not physically challenged. Therefore, parties dealing with physically challenged people can react accordingly to protect themselves from harm or at least make adjustments in their actions. Example: If you left your child at a day care with a caregiver who was confined to a wheelchair, you would be on notice, assume the risk, that without taking additional precautions, the provider may not be able to do some physical activities that may be necessary in some emergencies.
c. Persons who are mentally retarded. In contrast to the above analysis, the fact that persons who are mentally retarded or otherwise mentally impaired may not be discernible. Therefore, persons dealing with them may not be on notice of their capabilities. The courts are concerned also about the floodgates problem: People may use mental impairment as a defense in the extreme, i.e., "My I.Q. is a few points below what is average for childcare providers in this country and so I should be excused from all liability," or "I was under a great deal of stress and suffering from neurosis and so I should have a lower standard of care ascribed to me."
d. Professional people with advanced degrees. It would be unjust, a windfall of excusable neglect to ascribe to these people a standard of care lower than their actual knowledge.
e. Persons acting in emergency situations. Emergency situations bring to bear their own set of factual circumstances that call for immediate judgment of the actions involved. It would be unjust to ignore the unique pressures, factual circumstances, and human differences in emergencies and hold people acting in such situations to the same standard of care as people in calm, reasonable circumstances.
f. Persons who violate statutory duties. We are all held to be knowledgeable of the law, whether we are actually aware of a particular law or not. If we were not, people could use as an excuse that they did not know of a law. Once again, the floodgates problem would raise its head. Also, courts generally defer to legislative judgment in creating statutes. If the legislature deemed it of societal value to promulgate a particular statute, then the courts are bound to enforce it. These kinds of statutes are designed to avoid the problems of proof of standard of care and breach of duty. The harm is either of such a serious nature, or so prevalent, that the legislature has seen fit to treat the problem with a negligence per se statute.