If asked to devise a boarding method without any data, you might settle on this as a pretty sensible one. But the airlines do have data — and numerous studies have shown this is not a good way to board an airplane, in terms of time or customer satisfaction.

Both simulations and real-life experiments have proven the standard method to be the slowest out of several different ones. In 2012, the TV show Mythbusters recruited 173 people to compare four methods in a replica airplane interior and found that Southwest's boarding method was the fastest. A close second was allowing all windows seats to board first, then all middles, then all aisles (outside-in).

Jason Steffen, a physicist who got interested in plane boarding while stuck in line at the Seattle airport and subsequently conducted much of the research in this area, came up with an even better boarding system using computer models.

Steffen's method is a close relative of the outside-in method, but instead of allowing all window seat passengers to board first, it creates a choreographed sequence of them to avoid any aisle waiting at all.