Exchange a glance with someone，then look away. Do you realize that you have made a statement? Hold the glance for a second longer，and you have made a different statement. Hold it for 3 seconds，and the meaning has changed again. For every social situation，there is a permissible time that you can hold a person’s gaze without being intimate，rude，or aggressive. If you are on an elevator，what gaze-time are you permitted? To answer this question，consider what you typically do. You very likely give other passengers a quick glance to size them up(打量)and to assure them that you mean no threat. Since being close to another person signals the possibility of interaction，you need to emit a signal telling others you want to be left alone. So you cut off eye contact，what sociologist Erving Goffman(1963)calls“a dimming of the lights”. You look down at the floor，at the indicator lights，anywhere but into another passenger’s eyes. Should you break the rule against stating at a stranger on an elevator，you will make the other person exceedingly unc6mfortable，and you are likely to feel a bit strange yourself. 
     If you hold eye contact for more than 3 seconds，what are you telling another person? Much depends on the person and the situation. For instance，a man and a woman communicate interest in this manner. They typically gaze at each other for about 3 seconds at a time，then drop their eyes down for 3 seconds，before letting their eyes meet again. But if one man gives another man a 3-second-plus stare，he signals，“I know you”. “I aln interested in you”or“You look peculiar and I am curious about you”. This type of stare often produces hostile feelings.