How does the introductory paragraph contribute to the main ideas in the text "Spend time in any public space watching the crowds and you’ll see examples of what scientists call social influence — the varied ways people change their behavior because of the presence of others. Notice how individuals respond to orders and requests, go along with a group, mirror the actions of others, compete, and cooperate. We are finely tuned to the people around us, relying on each other for cues about how to behave so that we can efficiently navigate our social environments. The influence of others is so pervasive that we can experience it even when there is no real person there: we’ll adjust our behavior in response to an implied presence (say, a security camera and a No Trespassing sign) or an imagined one (“What would my mother say?”)."