Piggy responds to challenges to his authority by shrinking back.
When Ralph blows the conch and brings the boys together, Piggy tries to keep order by learning their names. The boys give him “simple obedience” and everything is going well. Then Jack and the choir show up, with Jack in charge. This throws Piggy off.
Piggy asked no names. He was intimidated by this uniformed superiority and the offhand authority in Merridew’s voice. He shrank to the other side of Ralph and busied himself with his glasses. (ch 1)
Jack immediately questions Piggy’s authority. Piggy tells him that he has the boys’ names, and Jack scoffs, saying that he just took down first names and those are “kids’ names.” He wants to be referred to by his last name, like a man. Piggy tries to object, and Jack shuts him down.
“You’re talking too much,” said Jack Merridew. “Shut up, Fatty.” (ch 1)
Ralph tells him that the name is Piggy, and all of the boys laugh. That is the end of Piggy’s authority. He is a joke now. What little obedience and respect he had, Jack took from him.
Piggy started off well. He was intelligent and tried to be organized. He even tried to learn the boys’ names, when no one else bothered. Yet he could not compete with Ralph’s beauty and Jack’s arrogance. He was relegated to second tier, and mostly ignored from then on.
On occasion, Piggy got so annoyed that he spoke up. Yet it was easy for the others to scoff at him and dismiss him. He got frustrated, angry, and gave up. This is why even though he was the most intelligent, he did not ever get in charge.