For public speakers the body language news is both good and bad.

The good news is that you are already an unconscious expert, for the most part, in reading some of the body language cues and the concomitant underlying emotions of people familiar to you. For example, arriving home, you can tell in an instant if your significant other is in a bad mood, right? Or at work, you know instinctively if your boss is in a really good mood for some reason or another. Or you can tell when a colleague is stressed out and unlikely to help you with something.

Unfortunately, an audience is only somewhat familiar to you in that sense.

And that’s the good news. The bad news is that where you really need the help is in the subtler moments when the emotion isn’t so obvious, the stakes are very high, or that audience member is confronting you and you want to know what to do. At those times, being able to accurately read other people’s emotions can be extremely important and helpful for your work life or your life in general.

So speakers need a system that will reliably help us out in a certain set of settings and situations. We need a system that will allow us to continue to participate in one of those situations, talking and listening, without having to take time out to study the body language in isolation. And we need a system that will have a high degree of reliability.

I’ve developed just such a system over many years of working with clients and reading other people’s intentions through their body language. It’s simple and effective.

A couple of years ago, I flew down to a semi-undisclosed location in the southeastern United States to help train a group of Air Force Special Ops folks who were going to be deployed to a trouble spot in a Middle Eastern country. Their job was to parachute into the country, quickly establish relationships with the locals, and start building things. That, at least, was what they were willing to share with me.

Their question, sensibly enough, was how to ascertain the friendliness or hostility of the local people—fast, with some precision. Lives depended on getting that right. So I taught them the two-step technique I’m going to share with you.

First, I need to clear away some common misunderstandings about body language.

There is a huge mass of misinformation that has built up around reading body language over the past half-century. The research approach widely followed since World War II studied gestures as if they had specific meaning. In other words, if you put your hand to your chin, you’re thinking—in all circumstances—and so on.

The research began with specific gestures, like the peace sign and the upraised middle finger, that do have particular meanings, what the researchers called “emblems.” Each culture may have only a handful of such gestures, but the approach then colored thinking about all the other gestures we make. The hand-waving gestures we make when we’re talking were dismissed as meaningless and largely ignored.

Now, researchers have made some headway. The problem with the previous approach is not that such a reading of a particular gesture isn’t sometimes correct. The problem is that gestures are ambiguous, fluid, and multi-determined. So focusing on a particular gesture and insisting that it has a specific, singular meaning will get you into trouble. That hand on the chin may mean you’re thinking, or it may mean you’re tired and resting your head in your hands. Or it may mean you’re scratching an itch surreptitiously and trying to look wise while doing so.

So, if focusing on particular gestures isn’t reliable, what can you use to decode body language?   Next time – how to tap into your unconscious mind.  

This blog series is adapted from my new book, Power Cues:  The Subtle Science of Leading Groups, Persuading Others, and Maximizing Your Personal Impact, published May 13, 2014 by Harvard. You can order it here.