Why we keep looking for lost items

Looking for something? New research provides insight into why we miss things when they're uncommon.

"We know that if you don't find it often, you often don't find it," said Jeremy Wolfe of Harvard Medical School. "Rare stuff gets missed." Wolfe's comments came in a news release from Cell Press, which published a study on the phenomenon online in Current Biology.

Anyone who's ever tried to find the so-called needle in a haystack knows of what he speaks. But why does this happen?

In a new study, researchers say that people who look for common things don't stop. "When nothing is there, they don't give up on the response," Wolfe said.

'Adaptive behariour'

"It's all terribly adaptive behaviour for a beast in the world. If you know berries are there, you keep looking until you find them. If they are never there, you don't spend your time hunting."

When something is rare, we try hard to look for it, but "we aren't well-built for that and make more errors than we'd like," he said.
 

What to do in places like airports, where security screeners have to look for uncommon objects like weapons? Wolfe said it might be wise to prime people at the beginning of shifts by having them search for common things, then let them go on duty and look for rare things.
 

The researchers plan to test their theories in airports and in health clinics, where medical employees look for rare things like tumours. - (HealthDay News, January 2010)