Big Brother might not actually be watching, but several studies show that the mere feeling of being observed may help prevent crimes. Security companies have been putting images of seemingly watchful eyes on signs for years, but new research seems to demonstrate that the technique is more than a piece of eye-catching marketing. 

According to Psychology Today, there's a system in the brain devoted to noticing where other people are looking. This "gaze detection" system is partially subconscious: It usually registers as a feeling of unease or heightened awareness, rather than a fully articulated thought. What's especially interesting about this system is its incredible sensitivity. It differentiates automatically between direct eye contact and someone simply staring in your general direction (looking at something over your shoulder, for instance). 

This "gaze detection" principle is now being studied by several law enforcement agencies. The Daily Mail reports that the police department in Nottinghamshire, England, began putting up signs with Police Inspector Nick Butler's eyes on them. After 18 months, they observed that crime had fallen 37 percent. In another study by Newcastle University, putting signs with eyes on them around campus bike racks was shown to reduce theft in those areas by 63 percent. 

These studies are a potentially useful tool for law enforcement agencies in need of a peaceful crime deterrent. But beyond their practical implications, they're also a reminder that humans have developed an amazingly complex system of non-verbal communication. Plus, they explain that uneasy feeling you get when when you catch someone staring at you from the corner of your eye.

[h/t Smithsonian]