If you are unhappy, does starting to greet your neighbor makes your happier? Or is it the other way around, when you are happy you greet your neighbor.
This sounds like a "one little weird trick to boost your happiness: greet six neighbors."
The important factors are the other things: having a high income, living in a good neighborhood, and and being a good community member. These increase your wellbeing, then of course you'll say hi to everyone.
People in low-income and "bad" neighbourhoods actually stand to gain a lot more by knowing their neighbours because they get a lot more out of community solidarity when there's trouble, they'll have networks to identify trouble earlier, etc.
This sounds like a "one little weird trick to boost your happiness: greet six neighbors."
The important factors are the other things: having a high income, living in a good neighborhood, and and being a good community member. These increase your wellbeing, then of course you'll say hi to everyone.