科学美国人60秒:Baggage Screeners Detect Danger Better with More Danger to Detect

Practice makes perfect. And that may be especially true for the security agents who screen your luggage—because a new study finds that transportation security officers become better at detecting threatening items when they appear more frequently.

Remaining on the lookout for hidden weapons can be mentally exhausting, particularly when the items in question are so rarely seen. That fatigue could translate into missing something deadly when it finally does show up.

So researchers put some newly trained security officers to the test. They asked the agents to eyeball the x-rays of five sets of bags and call out if they saw any guns, knives or bombs.

In the first three sets and in the last one the banned objects were few and far between. But the fourth set was a jackpot.

Turned out that the agents were better at spotting danger when there was more danger to spot. And this eagle-eye acuity carried over to when the threat level once again dropped. The findings can be seen in the Journal of Vision. [Jeremy M. Wolfe et al., Prevalence effects in newly trained airport checkpoint screeners: Trained observers miss rare targets, too] 

The results suggest that airport security might be beefed up by letting agents spot a simulated stockpile of arms—before they scan for the rare real things.

—Karen Hopkin