Because it lacks the grammar of a spoken/written language, body language is less formal and precise, communication researchers say. But body language does have some structure. Researchers have identified five basic types of nonverbal communication. They include emblems, which are nonverbal acts, such as shaking a fist, that can easily be translated into words, and illustrators, which emphasize speech, such as shaking one's head. Regulators indicate that the other person should start speaking with a gesture such as a head nod -- or, in the case of pacing and fidgeting, hint to them that it's time to wind things up. Adaptors are movements that primarily make a person more comfortable, such as shifting positions while listening. Affect display, the general category that includes movements and postures conveying emotions or thoughts, especially unspoken ones, is the type of nonverbal behavior that probably is the most important to us [source: Mehrabian].
Can body language be read like a book? Some experts in psychology, law enforcement and intelligence agencies believe that it can, particularly by analyzing the brief, subtle variations in a person's facial expressions, which are known as microexpressions. By systematically going through all the possible configurations of the human facial muscles, researchers Paul Ekman and Wallace Friesen have been able to identify about 3,000 different configurations, some of which are involuntary, that have apparent nonverbal meaning. They created the Facial Action Coding System (FACS), a tool for gleaning meaning from expressions [source: Gladwell]. Today, FBI agents and other investigators often receive training in microexpression analysis and use it when they question suspects [source: NPR].
Experts caution that it's also easy to misinterpret body language, by taking it out of context what is normal for that particular person. Author and consultant Carol Kinsey Goman, for example, recalls giving a presentation in New York to the chief executive of a financial services company. The head honcho sat at the table with his arms tightly crossed, without smiling or nodding encouragement, and at the end, simply said "thank you" without making eye contact and left the room. Given all those seemingly negative cues, Goman was startled when the man's secretary told her that he'd been favorably impressed by her. If the CEO hadn't liked what he'd heard, the secretary explained to Goman, "he would have gotten up right in the middle of your presentation and walked out" [source: Goman].