Arrogance is the behaviour of a person [when they feel that they are more important than other people, so that they are rude to them or do not consider them]. 

第一层： they feel that they are more important than other people, so that they are rude to them or do not consider them，结果状语从句

第一层为第二层when引导的时间状语从句

第二层方括号内的句子，成为主句Arrogance is the behaviour of a person的时间状语