The ability to decipher the language of non-verbal communication is truly a gift. But most people aren't as conscious as they should be about how they hold their bodies, and what the body language of others really conveys.

Robert Green, in The Laws of Human Nature, tells the fascinating story of Milton Erickson, one of the most influential psychotherapists of the twentieth century. At 17, he was struck with polio, paralyzed and confined to his home for several months before regaining his ability to speak and walk. In the meantime, he spent his minutes and hours observing his seven sisters, one brother, parents and private nurse interact with each other. He noticed that very often their facial expressions and body movements did not match with what they communicated with words.

Reading and displaying nonverbal communication are valuable skills

Over time, Erickson became a master of interpreting people's non-verbal communication. He was able to tell that a woman was cheating on her husband by the way she held her legs tightly together with one foot wrapped around the other ankle. He knew when his secretary had her period by the heaviness of her typing. And he could accurately guess a person's profession by the appearance of their hands, how they walked and held their heads, as well as according to inflections of voice.

While people close to Erickson felt as if he had psychic powers, his observational talents were merely a result of studying people intensely over long periods of time. It's the same way in which fortune-tellers and psychics do what they do, Green writes.

So, if the study of non-verbal communication can yield such interesting information, it behooves you to get better at interpreting it, or at least honing the way you display your own body mechanics, facial expressions and tone of voice. Here are what a few experts have to say.

Be careful with eye contact

When you are doing the speaking, you should look the person you're talking to directly in the eyes, but not so much when you're the person listening. "[M]aking eye contact while your interlocutor is speaking actually harms your perceived competence," writes Jack Nasher in Convinced: How to Prove Your Competence and Win People Over. "Direct eye contact with the speaker is associated with a low status, possibly because it is interpreted as a submissive gesture--servants look at their masters while they take their commands." Also, too much blinking undermines your credibility because it makes you appear anxious.

Resist the urge to look at your phone

You might believe you can be just as present and involved in a conversation if you occasionally look at your phone. But whether you intend to or not, you're sending the message that the people you're talking with aren't as important as whatever text, snap or post is on your device. Plus, scads of studies have been conducted which show the negative effect this behavior has on interpersonal relationships and personal integrity.  "To treat the person standing in front of you as secondary to your phone, is usually, as the kids say, a micro-aggression," Henry Alford, author of Would It Kill You to Stop Doing That: A Modern Guide to Manners, told The New York Times. "Never be the first person in the group to whip out his phone."

Better yet, put your phone out of your reach

It's because researchers have found that people with access to their smartphone smile less at strangers, compared with those without devices. In a study published in Computers and Human behavior, participants were told to hang out in a waiting room with other people, with half having their smartphone and the other half without it. The participants who could amuse themselves digitally showed significantly fewer smiles than those without phones. "[P]hones are altering the fabric of social life," the authors write.

People alter their tone of voice depending on social status

In a study published in PLOS One, researchers asked 48 participants to test a supposed new method of online interviewing and were presented with images and background information on three fictitious male employers. The fake profiles were intentionally crafted so that one came off as prestigious, another seemed dominant and the third being neutral. When interviewed by the first two employers--prestigious and dominant--participants' voices became higher pitched. No change in pitch was noted when they were interviewed by the neutral persona. In essence, people change their tone of voice when in an anxiety-inducing context, without even being aware of it. "These manipulations in turn affect the way we are perceived," the authors write. "Just like body posture, the language we use, or our facial shape and expressions, our voices are part of the arsenal of signals that affect perceptions of social status."