This is common sense, but it's nice to see it validated by more systematic study, and I'm happy to see people writing about it, so thank you for this article!
I think it's also important to have good relationships with your immediate neighbors: people in your apartment building, people in the houses next door, and the people who live on your block or in your area.
My neighbors have helped me out in a few binds, and I've helped them out too. Not only that, but everyone is safer when people in a community know each other. I think our modern global capitalist society has under-emphasized the importance of social bonds in maintaining prosperity. I am glad to see people thinking about this sort of thing.