If both boys and girls had been on the island, things would have been very different. To begin William Golding would have had to add in some thoughts to change some of the events that happened during the course of the novel. Another thing he would have to do is put more perspective in his writing, because girls would have a very different view of what would need to be done than boys, most girls would not be as violent anyways. Non-violent girls would therefore change the theme of the story, so it is probably a better idea that he kept them out.