One of the main causes of rage is perceivable inequality. If a plane has a first class section, the likelihood of an unruly or noncompliant incident occurring is 3.84 times more likely.
When all passenger board from the front and walk past the first class section, an incident occurring amongst first class passengers is 12 times as likely. For economy passengers, it's only 2.18 times as likely in comparison to economy passengers boarding from the middle.