You might examine Chapter Seven as part of answering this question, which contains a key episode when the boys pretend to hunt a pig who is played by Robert. As Jack and the other boys hold up Robert by his hair and threaten him with their knives, Ralph is rather disturbed to have the following reaction:
Ralph too was fighting to get near, to get a handful of that brown, vulnerable flesh. The desire to squeeze and hurt was overmastering.
This is a highly significant quote for a number of reasons. Up until this stage in the novel, Ralph has been the champion of civilisation, with Jack of course representing savagery. Even though Ralph has been the one who has been trying to get the boys to focus on building huts and keeping the fire going, and has not gone to hunt pigs, here we see that the descent into savagery is not something that he is immune to either. Golding therefore suggests that the evil, savage nature lurks in all of us and is something of a universal condition.