What does "people who heard voices were definitely in the bottom ten" convey in this context?

Question

> ‘All dark,’ Dudley said hoarsely, shuddering. ‘Everything dark. And then I h-heard ... things. Inside m-my head...’> Uncle Vernon and Aunt Petunia exchanged looks of utter horror. If> their least favourite thing in the world was magic, closely followed> by neighbours who cheated more than they did on the hosepipe ban,> **people who heard voices were definitely in the bottom ten**. They> obviously thought Dudley was losing his mind.> > _{*Harry Potter and the Order of the Phoenix*}As I understand, "*people who heard voices were definitely in the bottom ten*" is saying that Uncle Vernon and Aunt Petunia disliked people who heard voices(because it's in the bottom ten of their favourite list). But I'm not sure how it's relevant to the context. Maybe, they thought Dudley was losing his mind because he heard voices? What's the sense of it here?

Answer 1

In this context, it means that they dislike people who hear voices because it makes those people seem crazy. The Dursleys understand normalcy and cannot tolerate anyone who moves outside of that definition. The reason for this statement being in the bottom ten is because they dislike magic and magical people more than they dislike voices or cheaters etc.