Danger from people you don't know has a much broader cultural context, though. For some of my relatives in China, even making eye contact with strangers is unt

Danger from people you don't know has a much broader cultural context, though. For some of my relatives in China, even making eye contact with strangers is unthinkable. You don't look at strangers, you don't say "hi" to them, nothing. Growing up, walking past someone on the street, nodding, and smiling, even if I didn't know them, was normal. As population density goes up, that kind of policy becomes less workable, though. People try to insulate themselves from being psychologically overwhelmed from the sheer number of other people right there so they practice ignoring them. That's not true everywhere. In good neighborhoods in the newer stretches of Bengalaru (Bangalore), for example, it doesn't quite work that way. People talk. They figure out how to solve problems together, they move on. Your network is your wealth. My wife would probably have a heart attack in that atmosphere, though.