Trust is at the core of just about every type of human transaction in this relationship economy. And saying "trust me" is never enough and comes across as suspicious.

We must find different ways to win the trust of customers, employees, shareholders, vendors, friends, and neighbors.

One surefire way to gain trust is to master how you come across through your nonverbal communication. How does your body language make people feel about you?

Some experts suggest it takes less than five seconds for someone to form an opinion about you based on your appearance, body language, demeanor, and mannerisms.

First impressions begin immediately--even before you speak--because you're already communicating non-verbally.

Here are 6 ways you can get people to trust you by using the right body language.

1. Smile with your eyes.

People can see through fake smiles. Those who are genuinely interested in the other person will smile with their eyes and flash their pearly whites. It's heartfelt, warm, the facial muscles are relaxed, and it communicates to others two things: You're a safe person, and others can be open with you.

Such a smile is especially important when offering encouragement, praise, or meeting someone new. And, of course, be sure that your body language matches your message so that it registers positively with the other person.

2. Use a firm handshake.

Whether you're female or male, a firm handshake (not a crushing handshake, which has the opposite effect) coupled with "smiling eyes" is important for meeting new people, thanking or congratulating someone, or ending meetings and important conversations on a clinching note.

By the way, did you know that when you meet someone new and state your name with a firm handshake, it increases your chances 75 percent that the other person will remember your name?

3. Pay attention to your posture.

Remember when your mother harassed you as a teenager to stand up straight and not slouch in your chair? As it turns out, you should still listen to your mother. Bad posture could hurt you in a transaction, as it may send the wrong message about a lack of confidence or a closed-off personality.

Think open posture (arms and legs spread in a relaxed manner instead of crossed or folded) which shows confidence.

Avoid both slumping and rocking back and forth in your chair (or leaning back). Slumping conveys disinterest, rocking or leaning back says you're bored. Instead, lean forward when listening to someone speak which indicates an active interest in the speaker.

4. Watch your spacing.

Have you ever felt uncomfortable when talking to someone because he was invading your personal space? Culturally in America, if you're not intimately involved with the person, that's a no no. But what exactly is appropriate for distance?

Anthropologist Edward T. Hall answers that question in his book, The Hidden Dimension, where he discusses how space influences communication. Hall classifies these "space bubbles" or distances in four types:

  • Intimate Distance (Distance: Touching to 1.5 feet): Reserved for very close relationships, like your spouse.
  • Personal Distance (Distance: 1.5 feet to 4 feet): This distance is reserved for friends and co-workers where close contact is the norm in the work setting; however, it is a no-contact distance. "Where people stand in relation to each other signals their relationship, or how they feel toward each other, or both. A wife can stay inside the circle of her husband's close personal zone with impunity. For another woman to do so is an entirely different story," states Hall.
  • Social Distance (Distance: 4 to 12 feet): This is reserved for impersonal business or casual conversations. People are very much aware of the presence of one another, but they have good physical boundaries and don't interfere with each other.
  • Public Distance (Distance: 12 to 25 feet, or farther): This is the distance reserved for public speakers and/or public officials or for anyone on public occasions.

5. Maintain eye contact.

If someone avoids eye contact, you'll most likely pick up the other person's discomfort (which can be a sign of dishonesty). If you're dealing with an extremely shy person, ease his discomfort by asking questions that will help open up the conversation.

Typically, we maintain eye contact 30 to 60 percent of the time. More than that is welcome, as it signifies that you're interested in what the other person has to say.

Now, it's okay to give your eyes a quick break so you're not being the creepy starer. You can look away to pick up your cup of coffee, then return to a warm gaze.

6. Mirror the other person's behaviors.

You've been there before -- the conversation is hitting on all cylinders and both parties are totally engaged.

When the magic happens, it's common to see both sides subtly imitating each other's posture, stance, gestures, or facial expression. That's because mirroring nonverbal behaviors creates the sense that you're on the same page, which conveys feelings of trust.

William Maddux, professor of Organizational Behavior at INSEAD, tested the impact of this behavior on business negotiations.

He assigned one group of MBA students to subtly mirror their partners (e.g., lean in when the other leans forward), while the other group was told not to mirror.

The results? In the "mirroring" group, the two parties reached a deal 67 percent of the time. The group that was told not to mirror reached a deal only 12.5 percent of the time.