Your nonverbal signals don't always convey what you intended them to, in fact, when people read your body language, you can count on them making five major mistakes.

Body language was the basis for our earliest form of communication when the split-second ability to recognize if a person or situation was benign or dangerous was often a matter of life or death.

Today, nonverbal signals play a key role in helping us form quick impressions. But, as innate as this ability may be, not all of our impressions are accurate. Although our brains are hardwired to respond instantly to certain nonverbal cues, that circuitry was put in place a long time ago – when our ancient ancestors faced threats and challenges very different from those we face in today's modern society. The problem is that the world has changed, but our body reading processes are still based on a primitive emotional reaction that hasn't changed much since humans began interacting with one another.

For example: In our prehistory, it may have been vitally important to see an approaching person's hands in order to evaluate his intent. If hands were concealed they could very well be holding a rock, a club, or other means of doing us harm. In business interactions today, with no logical reason to do so, we still instinctively mistrust someone who keeps his hands out of sight -- in his pockets, below the table, or behind his back.

The following is adapted from my new book, "The Silent Language of Leaders: How Body Language Can Help – or Hurt – How You Lead." Here are the five mistakes people make when they read your body language:

1) They won't consider the context.

When it comes to body language, context is king. You can't really make sense of someone's nonverbal message unless you understand the circumstances behind it. Context is a weave of variables including location, relationships, time of day, past experience, and even room temperature. Depending on the context, the same nonverbal signals can take on totally different meanings.

Your team members, and colleagues won't always have access to this insight. So if you yawn in a staff meeting because you were up early for an international business call – let people know why you're tired. Without this context, you'll look like you're just bored.

2) They'll find meaning in one gesture.

People are constantly trying to evaluate your state of mind by monitoring your body language. But all too often they will assign meaning to a single (and sometimes irrelevant) nonverbal cue. And, since the human brain pays more attention to negative messages than it does to positive ones, people are mainly on the alert for any sign that indicates you're in a bad mood and not to be approached.

So – you may be more comfortable standing with your arms folded across your chest (or you may be cold), but don't be surprised when others judge that gesture as resistant and unapproachable.

3) They won't know your baseline.

One of the keys to accurately reading body language is to compare someone's current nonverbal response to their baseline, or normal behavior. But if people haven't observed you over time, they have little basis for that comparison.

Remember this when meeting people for the first time. They won't know that you habitually frown when you are concentrating. (And you may not realize it either unless you ask a friend or coach for feedback.) Others will most likely think the frown is a reaction to something they said or did.

4) They'll evaluate you through an array of personal biases.

There is a woman in my yoga class who liked me from the moment we met. I'd prefer to believe that this was a result of my charismatic personality, but I know for a fact that it's because I resemble her favorite aunt.

Sometimes biases work in your favor – an example of the so-called "halo effect."  But biases can also work against you. What if, instead of someone they like, you remind people of someone they despise? You might overcome it with time, but you can bet that their initial response to you won't be a good one.

5) They'll evaluate through a filter of cultural biases.

When it comes to nonverbal communication and cultural differences, you can expect to be judged by behaviors that include how close you stand to a colleague in conversation, how much or little you touch others, the degree of emotion in your voice, the amount of eye contact you display, and the kind of hand gestures you use. And what feels so right in one culture may be seen as highly insulting in another. (So before you attend that international business meeting, do a little research to on the nonverbal business practices that you're most likely to encounter.)

These are the five mistakes you can expect people to make. Understanding them, and trying not to make the same mistakes, will help you be a more effective nonverbal communicator.

Carol Kinsey Goman, Ph.D., is an executive coach, international keynote speaker and seminar leader, and the author of "The Silent Language of Leaders: How Body Language Can Help – or Hurt – How You Lead." She can be reached by email CGoman@CKG.com, phone 510-526-1727, or through her websites www.SilentLanguageOfLeaders.com and www.CKG.com