According to a study by physicists(!) the worst possible way to board a plane is by row number. In fact, it’d be more efficient to let people board the plane randomly. Other highlights from the experimental study include:

• The Window Middle and Aisle technique of boarding where passengers in window seats board first, followed by the middle and aisle passengers was more effective than both the row number technique and the randomized boarding technique.
• In the paper the physicists suggested their own boarding method that maximized the number of people who could use the aisle at the same time. This method turned out to be the fastest way that passengers could board the aircraft.
• How the different boarding times compare with each other depends, in part, on the length of the aircraft with the different methods scaling in different ways.

Source: Experimental Test of Airplane Boarding Methods

Via: Discover Magazine, Marginal Revolution