Posters with eyeballs shown to deter crimes

Crime deterrents come in many forms like cameras and security guards, but there's a surprising method that relies largely on psychology. Images of eyes looking out have been shown to make people behave.

Posters with eyes have helped one U.K. police department reduce thefts by 40 percent over a roughly 7-year period. Similar efforts helped another U.K. law enforcement unit deter shoplifting and university researchers send bike thieves elsewhere.

The technique is called eye image compliance which runs on the hypothesis that people become more aware of their behavior when they feel they're being watched. This could work particularly well with humans because they have a brain system attuned to where the glances of others are directed, a function called gaze detection.

Researchers are unsure how long eye image compliance remains effective in any given space and also if it's the stare that deters crime or just draws more attention to warning signs.

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