Answer:
It forces the boys to let go of some of society's conventions.
Step-by-step explanation:
When you go through the starting few chapters, you understand that the boys are on a "deserted" island, and they immediately realize that they are pretty much stranded, without a lot of resources and adult supervision.
So they (and you, the Reader) understand that they have to just let go of some of society's convention, and adapt more to that wilderness state of mind.