Humanizing Rules

CHAPTER 20RULE NUMBER THREE

What's the Point of Airport Security?

Next time you're catching a plane, take a closer look at airport security. Not too close, mind you, I don't want you to be detained! On the face of it, the reason we all go through the process is to protect passengers, staff, aircraft, and airports. Yet, as readers who are frequent flyers can attest, there are huge inconsistencies between airports – and indeed individual screenings – in who and what the process rejects or lets through. Fly often enough, and you'll experience false positives; times when you or your bags have required re‐scanning for no apparent reason. Equally, you can have times when your bag sails through the scanner, only for you later to discover that it contained an item you'd forgotten was there but which was not within the rules.

There's a lot we could criticise about this. Viewed through a cost‐efficiency lens, the security processes can often seem disproportionate, ineffective, or both. Yet, from a psychological perspective, there's a good argument to be made for designing them that way. What look like random and inefficient processes can – though this is not always the case – serve a useful purpose that might not be immediately obvious.

Those apparent inefficiencies aren't accidental. They're designed in a way that not only does the apparent job of screening passengers but also sends subliminal signals to two very different audiences:

The first audience is “bad actors” – people intentionally ...