Body language experts are people who evaluate non-verbal communication in contexts where an expert's opinion is required. Many people have the ability to evaluate body language to some degree, and some may even be quite good at making determinations about a person's thoughts based on body language. An expert in this practice is typically a person with advanced formal education in psychology or another discipline that focuses on body language. The opinions of body language experts can be useful in legal context, hiring decisions, and even therapy. Different experts may adhere to different schools of thought, but because this discipline focuses on getting results rather than proving theories, it is often easy to figure out which expert is superior.
The way in which body language experts operate depends on the expert and his or her theories about this science, but most rely on small involuntary movements and ways of positioning the body to make determinations about what the subject says or believes. It is important to understand that the movements themselves do not say anything except in relation to the individual's history, his or her personal psychology, and the situation at hand. An expert uses these cues as well as information about the individual to help identify his or her internal states. Most of the time, it is the individual's emotions and feelings that are betrayed by body language, not any factual information about questions being asked.
Experts of this type are usually psychologists with advanced degrees, although certain aspects of anthropology and other studies of humanity can have valuable insight into body language. In order to be considered an expert, an individual must have a high degree of accuracy that can somehow be documented empirically. Simply understanding the theories of body language is not enough to be an expert in practice. Using the theories quickly and delivering results is very important as well.
One of the most important uses of body language experts is related to law. This type of expert can be helpful when reviewing testimony to look for signs of deception and can also be used for witness preparation in order to create an appearance of truthfulness that most jury members will be unable to identify but will subconsciously understand. Body language experts can also aid in picking jury members. The admissibility of the testimony of this type of expert in court is not always assured, and in many cases body language experts are considered less convincing than polygraphs and other lie-detecting methods.
In some cases, body language experts can be useful in other disciplines where a person might be hiding an emotion. For example, experts of this type can be very helpful when trying to pinpoint why a politician does not come across as genuine and may be able to help him or her change the problematic body language. Employers might make use of this type of expert when trying to weed out disingenuous potential employees. The possible uses of this discipline are quite broad and depend more on acceptability than any deficiencies of the science.