We’ve heard many stories in the news about people illegally carrying firearms on their person or in their check luggage. To me and you, this seems like an impossible item to miss. How could someone not see this on a scanner? We blame the incompetent TSA agent for endangering lives. But it’s not that easy. Being able to perform this task is based on the cognitive principal of visual search.
Visual search is the task of finding a target amidst distracters (non-targets). In this case, we can think of the firearm as the target and TSA compliant luggage as the distracter. There is an accuracy slope associated with this visual search task: the larger the number of distracters, the less likely the individual is to find the target. In other words, the higher the percentage of luggage without firearms, the less likely TSA agents are to find a firearm.
Think of it as the old needle in a haystack metaphor. If you spend hours searching for the needle, you might actually miss it when you come across it. Your mind is fatigued and your attentional resources are dwindling from looking at similar pieces of hay over and over again. However, if there were many more needles in the haystack, you have a higher likelihood of finding all of them.
A TSA agent’s visual search task requires the utmost vigilant attention. However, our attentional resources decrease as the amount of distracters increase. This is true for everyone but a very tiny percentage of the population. If you had to be a TSA agent for a day, you would most likely follow suit.
The same is true for radiologists and doctors looking at x-rays. A staggeringly large percentage (about 15%) of breast cancer on mammograms is missed because of this same visual task issue. The same is also true for visual search tasks in air traffic control, quality control, etc.
Try it for yourself
Here’s a game based on the same principal. See how well you do! After you’re done, think about doing that for hours while standing. Not so easy, right?
http://www.gocognitive.net/demo/visual-search
Possible Solutions
So, what can be done about this?
Give agents more breaks/make shifts shorter
Giving agents time to rest and reconfigure their attention may increase accuracy in target finding.
Include periods of artificially high target prevalenceThat’s right! Put staged firearms and weapons through the checkpoints. If we increase the number of targets amongst the distracters (luggage), there will be an increase in both the reaction time to find them and also the accuracy in doing so.
It is up to the TSA to study cognitive psychology and incorporate these kinds of practices to make our airports safer.
For more information on this: https://en.wikipedia.org/wiki/Visual_search