A normal conversation between strangers involves more than talk. It also involves the dynamics of space interaction. If one person gets too close, the other person will back up. If the first person invades the other's space again, the other person will back up again. The person who finds himself or herself backing up is trying to increase the distance of the comfort zone. The person closing in is trying to decrease that distance. Most likely neither person is fully aware of what is going on. In the 1960s, American anthropologist Edward T. Hall was a pioneer in the study of human behavioral use of space. His field of study became known as proxemics.Hall said that personal space for people in the United States can be defined as having four distinct zones: the intimate zone within 18 inches of your body, for whispering and embracing; the personal zone of 18 inches to four feet, for talking with close friends; the social zone of four to 10 feet, for conversing with acquaintances; and the public zone of 10 to 25 feet, for interacting with strangers or talking to a group. Historians say that our standards of personal space began with the Industrial Revolution in the 18thcentury. In cities such as London and New York, people of different social and economic classes were suddenly crammed together, so they unconsciously developed a commonly understood code of courtesy to restrict the space around them. People exhibit nonverbal messages of discomfort when their zones are violated. Invaded people might tap their toes, pull at their hair, become completely rigid, or even become angry. As hall noted in his landmark work, a comfortable conversation needs to include the parameters of human personal space. This passage is mostly about  _  .
what nonverbal communication is human conversation the life of Edward T. Hall human behavioral use of space