Roger
The most obvious one in the Lord of the Flies that shows the importance of civilization is the change of Roger. At the beginning, as he wanted to hurt Henry, civilization made him do not do the wrong thing. However, after the civilization was gone, because there's no influence of civilization, he chose to hurt and kill Piggy and Ralph without thinking. The contrast behaviors shows that how important that the influence of civilization is to humans. The civilization which represent all the knowledge that people learnt from school, parents, and the society around them help limit people's behaviors and make the right choices.