Steve Roesler(photo left), principal and founder of The Roesler Group,  writes the following:

This is useful to everyone, especially in a career world that is so overwhelmingly global.

You'll find "experts" on body language and rants about the meaning of this gesture or that one. Much of this is true, with one huge caveat: you have to be patient and carefully synthesize the totality of the gestures and mannerisms in order to develop some degree of accuracy.

Humans produce about 50 distinct types of smiles but there's one distinction that really matters: between real and fake.

If we can tell the people who are showing what they're feeling from the people who are faking it, then we've got a really good indicator of who to trust and work with.

For years psychologists have thought that a real smile, which reflects felt, positive emotion, is signalled by upturned lips and crinkly eyes.

This genuine smile is named after the French physician Duchenne, who passed electrical currents through live subjects and took photos of their weirdly contorted faces.

Oddly enough when some people try to fake a smile they look like one of Duchenne's subjects: in pain. It has been suggested that 80% of us are unable to conjure up a fake smile that will trick others because we don't have voluntary control over the muscles around our eyes which signal the Duchenne smile.

Let's say that you're traveling to a country where you don't speak the language. You didn't have time to pick up a dictionary or a book of common phrases, so you'll have to get around using only hand gestures. At a restaurant, you try to indicate which dishes you'd like by nodding or giving the server a thumbs-up, but all you get is the opposite of what you wanted and an offended look. No one will look you in the eye, and one person seemed downright affronted by your attempts to point out on a map where you'd like to go. What gives?

Our body language exhibits far more information about how we feel than it’s possible to articulate verbally. All of the physical gestures we make are subconsciously interpreted by others. This can work for or against us depending on the kind of body language we use. Some gestures project a very positive message, while others do nothing but set a negative tone.

There's no punchline. Laughter is a serious scientific subject, one that researchers are still trying to figure out.

Laughing is primal, our first way of communicating. Apes laugh. So do dogs and rats. Babies laugh long before they speak. No one teaches you how to laugh. You just do. And often you laugh involuntarily, in a specific rhythm and in certain spots in conversation.

Communication is a central aspect of everyday life, a fact that is reflected in the wide variety of ways that people exchange information, not only with words, but also using their face and body. Scientists from the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, found out that we are able to recognize facial expressions in motion - for example in a movie - far better than in a static photograph. The video sequence needs to be at least as long as one tenth of a second to gain this dynamic advantage. (Journal of Vision, December 7th, 2009)

A facial expression can state a lot. A nod indicates understanding, a frown may say: "Please explain that again!" Scientists from the Max Planck Institute for Biological Cybernetics discovered that we are able to classify an expression much better when it moves naturally rather than when it is "frozen" in a photograph. In order to gain the advantage of dynamic information, we need to see the expression moving for at least 100 milliseconds. If the video sequence is shorter, our brain is less capable of interpreting the facial motion. Some expressions rely on changes in head orientation, for example, a nod or a shake of the head, others on the complex deformation of facial parts, such as wrinkling our nose to signalize disgust or a frown.

“A significant amount of communication occurs through body language. Though we can’t see our own, everyone else does. If you’re saying one thing and thinking another, your body language may well give you away.”

When it comes to body language, simply avoiding the most common mistakes and replacing them with more confident movements will make a big difference. Here you will find eight body language killers that will leave your audience underwhelmed and unimpressed. Train yourself to avoid them, and you’ll see that simple changes can make all the difference.

Have you ever been in a conversation in which you can never get a word in because the other person constantly interrupts you or just keeps going on and on? It is aggravating because verbal communication is typically a cooperative social interaction based on the exchange of information in a turn-taking manner. Taking turns while conversing is something that usually comes naturally (unless you are the interrupting-type mentioned above).

Sue Thomas was sure she was being fired from the FBI. She had been analyzing fingerprints for just a week, but had found the work unbearably tedious. When asked to report to her supervisor’s office, she was prepared for bad news. Instead, she was confronted with seven of the FBI’s top officers who were interested in discussing, of all things, her lipreading.

Sue is completely deaf, and her supervisors had noticed that during their interactions, she seemed particularly good at lipreading. Now they were interested in whether she could also lipread from videos. She told them that she could, as long as there was a clear view of the face.