Different cultures tend to have very different attitudes and norms about nonverbal communications. This can lead to problems between people of the cultures. A person from Culture A may engage in nonverbal communications that are common and indeed expected in his society, not realizing that he is offending the person from Culture B with whom he is communicating.
One of the most common American nonverbal communications that might offend people of other cultures is direct eye contact. Americans feel that this is a necessary show of interest, of sincerity, and of honesty. In some other cultures, however, it is seen as a disrespectful thing to do. Thus, when an American tries to make eye contact with a person from another culture, that person may be offended.
A second thing that Americans do in nonverbal communication is to touch one another more frequently than is acceptable in some cultures. This is particularly likely to offend when the touch is between people of different sexes.
A final thing that Americans often do is to touch the heads of children. Teachers often do this as do doctors. It is meant to be affectionate. However, in many cultures, this is considered to be very rude.
Americans dealing with people from other cultures might benefit by finding out which, if any, of these forms of nonverbal communication are offensive to the people they are talking to.