The city can be a cold place at times, and not just in terms of weather. Whether they're in the middle of the daytime bustle or walking at night, people in the city often seem to go to great lengths to avoid contact with one another in encounters on the street, creating an acute sense of loneliness and separation.
This aversion to interaction follows a common pattern. In the streets of Washington, DC, for example, people often pass each other without a single sign of acknowledgment of one another. The head and eyes are cocked straight with the purpose of avoiding meeting someone else's gaze. If eye contact should be made by accident, the eyes usually dart towards the ground, or their phone, if they happen to have one handy.
In other circumstances, people will just give each a cold, hard stare that seems to give the feeling that they see right through you as if you're not even there. This awkward and usually silent dance lasts for a couple seconds until the people pass you and they can stop avoiding interactions... at least until they encounter another person on the street, and repeat the same dance from before. It's especially common for people to give this treatment to beggars on the sidewalk, and it can be quite demeaning.
Coming from a small town where I was taught to greet people on the street because I knew so many of them, I have never fully understood why people are so averse to even simple interactions on the street. I can say, however, that this aversion can make the city, a place where one is surrounded by masses of people, give off an acute sense of loneliness, at least for a streetwalker. It can feel cold when people in the street seem to be pretending that you are not there.
However, it's easy to break this ice with a simple hello. Just saying "Hi!" or Hey!" or even just giving a nod or a wave when you see somebody can go a long way to combat the lonesomeness that the city street breeds. The key is to acknowledge somebody and not pretend that they do not exist. This acknowledgment helps to show to a person that they are somebody and not nobody in your eyes; it shows that they mean at least enough to somebody else to deserve a greeting.
Admittedly, it can feel awkward to try engaging strangers on the street. Still, just making a little effort to say hello can hold a much greater significance to the person being addressed than it would seem on the surface. It sure beats the cold stare at the very least and can serve to make the city a much less lonely place for both yourself and others.
So, next time you see somebody on the street, don't take part in the interaction avoidance dance; give a wave or maybe a smile, and say hello once in a while.