Liars will usually avoid physical contact.
Liars rarely touch others when they lie to them. This is a natural part of the fight or flight response and the subconscious mind won’t permit them to reach out because of it. This can prove helpful in intimate relationships, with family members or children since touching is a normal part of everyday life. Any form of touch reduction can signal that a person is at odds with another and that they might be hiding something. If touch isn’t normal, however, then measuring touch reduction won’t be possible. In this case, look for distancing behaviours instead like arm withdrawal or leaning away, especially in the torso as these are forms of distancing of which touch forms a subset. Touch is an aspect of closeness that is simply not tolerated well between those who have different ideas. Couples have even been shown to draw away from each other when they are generally unhappy with their relationship, and tend to touch themselves far more frequently than they touch other people.
Touch reduction is usually accompanied with stressful questions or when information is presented that creates anxiety. Closeness can also be useful when assessing someone because it will invoke distancing desires. When talking with a spouse or child, sit as close as that which you are accustomed to before taking up serious matters. If someone is hiding something, they will usually push away or even stand up looking for ways to exit or change the subject. Holding the hand of a child can be particularly useful when discussing matters of dishonesty. If they wish to exit the discussion, they will try to tug their hand away.