Many people don't realize that negotiation isn't just about what you say. Turns out there's a lot of valuable information hidden in people's gestures and facial expressions. Experts tell us that people's body language accounts for more than 90 percent of our impression of them and outweighs the words they use.

With that in mind, here are three not-so-obvious body language cues that may help you get the upper hand in your next negotiation.

1. The Pupils

It's said that the eyes are the "window to the soul," and that's certainly true in negotiation. You can learn a great deal about a person's state of mind by observing the size of his or her pupils. According to body language experts, when people are interested in or in favor of something, their pupils involuntarily dilate. Conversely, pupils constrict when someone is closed off or disinterested. So if you're seeing your fellow negotiator's pupils shrink, it's time to change things up and try a new tack. If the pupils remain wide, you could be close to a resolution.

2. The Hand Steeple

The hand steeple--with hands fingertip to fingertip as if praying--tends to be a gesture of strength and confidence. But the steeple can be a double-edged sword: it can also convey arrogance, or haughtiness in some cases. In negotiations, use it sparingly. If you need to show strength, you can break it out, but don't use it if you're trying to gain the person's confidence or connect with them on the same level. I once interviewed a guy who used the steeple gesture throughout his entire interview. It was a small thing, but it signified to me that he felt superior and perhaps too confident. His showy use of this gesture prompted me to check his employment records a little deeper, and I found indicators of questionable performance. That applicant didn't get the offer.

3. The Deceptive Touch

Remember the three wise monkeys in the Japanese proverb that "see no evil, hear no evil, speak no evil"? They are typically depicted covering their eyes, ears, and mouth, respectively. Think of those monkeys next time you're in a negotiation, because when your fellow negotiator makes a similar gesture--a quick, non-lingering touch to the mouth, eye, ear, or nose--they may be trying to deceive you (or are unsure of what to say), according to body language experts. When people make the same gestures but with a longer duration--and sometimes using the whole hand instead of a finger--it means they think the people they are listening to are not truthful, or they may be pondering the honesty of the words.

These three are simple little signals, yes, but if you keep them in mind next time you walk into a negotiation of any kind, you may find they give you a significant edge.