In big cities, people tend to have a stressful routine. There are the traffic jams, the bad air quality, and the lack of natural options for leisure (e.g. green parks); all these issues, generally, turns people to more isolated and lonely, even they are in a crowd. Whereas in small cities, generally, people have a more relaxed life, with no traffic jams, good air quality and, so, they tend to be more friendly and meet their neighbors!