What similarities are there between Roger and Simon in the Lord of the Flies?

William Golding's Lord of the Flies focuses on a group of boys who are stranded on an island after the airplane they are on crashes. The young boys find themselves on an uninhabited island and are left to fend for themselves when they realize there are no adults with them. Apart from these circumstances and their similar ages, there are few other commonalities between Roger and Simon.
Simon is viewed as the epitome of morality throughout the novel, and is commonly accepted as an almost Christ-like figure. His actions throughout the novel are motivated solely by good; he strives to do what is considered right, even if there is no benefit to him. Simon even offers up his own life in an effort to enlighten the other boys about the "beast" and assuage some of their fears.
Conversely, Roger acts as a foil to Simon's character. His actions often agitate or harm the other boys on the island; he seems to take great joy in inflicting pain on those around him. These actions culminate in Roger's choice to take Piggy's life.
Part of the brilliance of Golding's novel is its ability to demonstrate how easily one's actions can move from civil to savage. The characters of Simon and Roger appear similar on the surface, but the lack of control and authority on the island quickly leads them down separate paths.