Searching for the upper hand in business or romantic relationships? Look no further than the incomparable power of eye contact.

There's a trick to interpersonal relationships that once you know it, you'll wonder how you ever lived without it. If you want to be more assertive in the office or express confidence while out at the bar, the key to success has been staring you right in the face all along. Or more accurately, hasn't been staring at you, because most people don't make effective eye contact – which is exactly why it's such a powerful tool.

You've probably already been on the receiving end of someone who, purposefully or not, was an avid user of eye contact. Perhaps the salesman who talked you into the five-year service plan on your television or the girl from your college macroeconomics class who turned you into a humble, stuttering manchild every time she pierced your eyes with hers. These people all leave an impression because they're clearly communicating two things – confidence and awareness.

When people lock eyes, it elevates any conversation from casual and impersonal to something more meaningful. There's a reason why when we believe someone to be lying we challenge them to “Look me in the eye and say that.” It's harder to lie while making eye contact, because you've established a personal connection with each other. Personal, but not always mutual, which is why the person initiating and holding eye contact often holds the upper hand. Studies have shown that children learn more when eye contact is present, people listen more attentively, and flirtation is more openly received.

Knowing that eye contact is important is the first step in weaponizing it for your every day use. The second step is simple in theory, but difficult in practice. Eye contact can feel unnatural at first, or awkward, but that's simply because it's an unused tool in the box. The most important rule to remember is that eye contact is not staring. Don't lock eyes and bore holes through their heads or you'll come off as threatening. And don't pick a spot on their face, like an eyebrow or a mole, for two reasons: One, that's not eye contact and two, they'll feel as though you're staring at a flaw. Which you are.

To make effective eye contact, look into their eyes and maintain that contact for a count of three or five seconds. Any longer and you risk making them uncomfortable or threatening them. While you're talking, it is better to keep your eye contact a touch on the shorter side and look around as you speak. When listening, it is more beneficial to maintain slightly longer periods of contact, indicating your (hopefully sincere) interest. When you break eye contact, don't look down, a sign of submission, but rather up (remembrance) or break contact with a smile or laugh, as long as it's appropriate. After breaking eye contact, be sure to resume it.

Whether you're looking to flirt with a good looking woman or haggle down that new High Definition television, by making eye contact you establish a higher level rapport with them and differentiate yourself from the faceless others, stammering and shifty-eyed. By making eye contact, you show signs of confidence and interest, making you a power player in love and business.