Almost anyone who has taken a long flight has dug their fingernails into the armrest, clenched their teeth, and curled their toes, all in an attempt to prevent themselves from becoming swept up in a fit of air rage.

The countless frustrating aspects of flying from being stuck in the middle seat to long delays, make it easy for a well-mannered person to turn into a chaos causing barbarian. A new study suggests that the annoying minutiae of air travel is not to blame, but the friction caused by the existence of first class.

Katherine Decelles, an associate professor at the University of Toronto, and Michael Norton, Professor of Business Administration at Harvard Business School, published a study that looked at data from a large anonymous international airline to see if the presence of a first class would make incidents of air rage more likely. “Turns out it does, just knowing it’s there,” said Norton on Boston Public Radio Monday.

Norton said the mere existence of first class on a flight is equal to having the passengers in the economy class waiting nine hours. “When you’re stuck in the seat with peanuts that stink, that’s terrible no matter what; but when you know there are those people up there, it’s even worse to be stuck in that seat,” said Norton.

In addition to inducing air rage in the economy class, first class is also populated by entitled passengers who have triggered many of the air rage incidents covered by the media, says Norton. “A lot of the air rage incidents.... are actually people in first class who are flipping out because they are not allowed to play the game they wanted,” said Norton.

Listen to our interview with Professor of Business Administration at Harvard Business School Michael Norton above