The clearest example of verbal abuse and its consequences is found in the character whom the boys call Piggy. There is a progression to appreciate.
After the plane crashes, Piggy and Ralph are together and Piggy tells Ralph that the boys at school called him by the nick name "Piggy." At this revelation, Ralph laughs, as he thinks this is funny.
When Ralph and Piggy find the other boys, the other boys led by Jack poke fun of Piggy right away for his name and his appearance. This continues throughout the novel, even though Piggy is a very intelligent boy that helps the group in very important ways.
By chapter four, the taunting of Piggy gets more serious. After Jack comes back from the hunt, he not only mocks Piggy (this time for his whinny voice), but he also hits him hard. From this we can say that verbal abuse now turns into physical abuse. Later on, Jack would even steal Piggy's glasses, so that they would be able to make fire. There is little care for Piggy.
Finally, in a fight between Ralph and Jack, as Piggy tries to talk sense and order into the boy, Piggy is killed by a rock that is thrown down on him by another boy (Roger). In light of this we can say that verbal abuse eventually lead to death. When we dehumanize people, it is easier to harm them.