Whether you know it or not - and most of the time you don't - when you're interacting with other people, you're constantly sending and receiving information without speaking or listening. These nonverbal (not using words) cues help reinforce your message and help others to assess your state of mind. Quite often, nonverbal cues will reveal thoughts and feelings more directly than spoken words.
In the card game poker, players look for clues from other players that indicate the strength or weakness of their cards. These clues can be based on changes in their betting patterns or changes in how they sit, gesture, move or speak. These are called "tells” and are good examples of nonverbal communication.
Two research studies from the 1960s (Mehrabian & Wiener, 1967 and Mehrabian & Ferris, 1967) suggested that 55% of communication is body language, 38% is the tone of voice, and 7% is the actual words spoken. That's 93% of communication being nonverbal! This is now considered to be a bit of an exaggeration. These days experts agree that you can't say "x% of all communication is nonverbal", (but you might see reference elsewhere to the 55/38/7 ratio) but they would agree that nonverbal communication is very important.
Nonverbal communication can take many forms:
Perhaps the most expressive form of nonverbal communication is your facial expression. A smile conveys happiness or approval, and a frown conveys unhappiness or disapproval. Our facial expressions may reveal how we really feel about something; you might say "that's fine", but your scowling face would indicate otherwise. Facial expressions also send signals about what we want to happen next. Your unhappy face, for example, might show that you’re not impressed with the way the conversation is going – and that you want it to take a different course.
While the face might be a dead giveaway, you can learn a lot from the gestures people make. Frequent and wild hand gestures usually indicate engagement and excitement, while in a meeting if someone is fidgeting with their pen, it usually indicates that they're bored, or distracted; finger pointing has entered the language as an expression of blame or responsibility.
Eye contact usually indicates sincerity, trust and warmth in communications. Prolonged eye contact or staring can be rude, uncomfortable or aggressive, while not making eye contact at all might be down to shyness or indicate insincerity.
Posture is also useful in conveying information: crossed arms can indicate that a person feels defensive, unhappy, or closed-off, while standing with your hands on your hips might show that you're ready for a confrontation. Sitting up straight coveys focus and attention, while slouching in a chair indicates boredom or indifference.
Tone of voice is your ability to change the meaning of your words by changing your pitch, intonation, volume, or tempo. Changing your pitch or tone shows that you're engaged. If you speak in a monotone, it indicates that you're bored or not interesting in the topic; shouting shows aggression, while speaking quickly probably means that you're excited. Tone of voice is particularly important in telephone conversations, as it's the only non-verbal cue available to your listener.
How you look also communicates an impression. Clothes, accessories, colours, styles as well as piercings and tattoos all send messages about who you are and what you value. Think about who wears a suit, for example.
This generally refers to the physical distance between two people in a social or work environment. You don't like people to stand too close to you, unless they're family or friends, perhaps. Standing too close to someone is a sign of aggression, or perhaps a sign that you're not good at picking up personal cues.
Try the following tips to read the nonverbal signals of other people and improve your own communication skills
Mehrabian, A., and Ferris, S. R. (1967). Inference of attitudes from nonverbal communication in two channels. Journal of Consulting Psychology, 31(3) pp248–252
Mehrabian, A., and Weiner, M. (1967). Decoding of inconsistent communications. Journal of Personality and Social Psychology, 6 pp109-114