What evidence is shown that the boys are becoming increasingly barbaric?

at first, the kids act very civilized. But through-out the book, they begin to be more barbaric. you can tell this because of these reasons. First, Jack becomes obsessed with killing the pigs, then becomes a bloodthirsty devil. Another reason is because of the fear that they all have of the monster. as jack becomes more scared of it, he begins to want to overpower the monster, and be able to fight back. That is why he starts to become make weapons and lead hunts. Then jack gets the kids to follow him by threats.