Is Golding's view of human nature optimistic or pesimistic?

Golding’s view of human nature is clearly pessimistic. Piggy represents optimism (positive i.e. the good things) in society. Though when Piggy dies, his optimism and point of view (which effects Ralph’s positive nature) dies with him. Jack represents pessimism (negative i.e. evil in society).

The purpose of Golding’s novel, Lord of the Flies, is to show how people act with just their human instincts. The boys represent society. Piggy represents good in society (i.e. morals, rules, fairness, kindness). Jack on the other hand represents bad in society (i.e. evil, dictatorship, violence).
The little boys/ little ones represent society and in the novel it shows what Golding thinks society sways towards, evil or good, optimism or pessimism.
The boys are on a tropical island where they are put in circumstances where they have to use their human instincts/nature to survive, they have to go with what they think is the strongest team, which team they will have the best chance of surv...