The tiny gesture can have a massive impact on your safety.

In the world of air travel, there are many quirks that we don’t quite understand. Why are peanut snacks the norm despite the frequency of peanut allergies? Why do we board planes the way we do? Why do we have to return our seats to an “upright position” for take off and landing? As long as we’re wearing our seatbelts, does it really matter?

Yes, yes it does. As reported by Condé Nast Traveler, straightening your seat can indeed be the difference between life and death. The reason for returning your seat to that upright position (ditto for folding your tray table up) has to do with evacuating the airplane safely in case of emergency

“The primary exit path is up or down the center aisle to the doors. But there’s also another path people don’t think about: from the window seat to the aisle,” Candace Kolander, Air Safety, Health, and Security Coordinator for the Association of Flight Attendants tells Condé Nast Traveler. If you’re sitting behind a seat in a reclined state, it can prevent you from getting to the center aisle as swiftly as possible. The majority of accidents occur during take off or landing, hence it being mandatory during these phases of your flight.

The Federal Aviation Administration requires that aircraft can be evacuated in less than 90 seconds.This is no random designation: 90 seconds is all it takes for the plane’s jet fuel in the tanks to explode. Needless to say, in case of an emergency, you should never grab your luggage as it not only puts your own life at risk, but others trying to evacuate the plane safely. 

Sure, raising your seatback in the middle of a riveting book chapter or while zonked out in dreamland can be a minor nuisance. But it’s a very, very small price to pay for what con potentially be a life-saving act.

As for the peanut snacks and nonsensical boarding processes? We’ll have to get back to you on those two.