I've lived in suburbs where I had a good idea of who lived in each house, talked to some of them semi-regularly, and kids ran around the neighborhood together every day, and I've lived in neighborhoods where everyone stays inside and nobody interacts with each other and even the few group things explicity set up (neighborhood street potluck, chili cookoff at the attached park) couldn't be sustained. I moved directly from the former to the latter, so the difference was stark.
I think it has much more to do with demographics and type of people that happen to be living there, and whether there's an existing community. The more lively neighborhood in my case was in a "worse" neighborhood with cheaper houses, while the new neighborhood was all newly build housing. We were all starting from scratch with each other, with some people maybe having a year or so more history than others (as they staged builds 5-10 houses at a time). Community is a frail thing, and needs to be tended or it will wither, and sometimes it dies before it even has a chance to flourish.
I think it has much more to do with demographics and type of people that happen to be living there, and whether there's an existing community. The more lively neighborhood in my case was in a "worse" neighborhood with cheaper houses, while the new neighborhood was all newly build housing. We were all starting from scratch with each other, with some people maybe having a year or so more history than others (as they staged builds 5-10 houses at a time). Community is a frail thing, and needs to be tended or it will wither, and sometimes it dies before it even has a chance to flourish.