It seems as if each character represents someone in society. Ralph would represent a leader since that is what he is. Piggy is the genious, Jack is the dissenter gone wild and Ralph tries really hard not to fall into any savage behavior; in other words, he tries hard to stay focused on the task at hand which is getting rescued. Ralph can also be compared to human conscience and reason, both of which need to be in tact in order to maintain civility among chaos. Ralph is the counter-balance to Jack who freaks out, forgets who he is, and chooses to lead a life of anarchy (as long as he's in charge of it.)
So Ralph would be conscience and reason among chaos, but he too is also human and falters. He too ends up fighting and falling into the chaos of the sociey in which the boys find themselves.
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