I looked for things like how well they kept up their yard and I didn't want to be next door to an established Live Oak. They drop leaves and tiny acorns all over your property.
You are right, some neighborhoods are very social and friendly, others not so much

Not everyone does.

to the OP: I didn't really need to check out the neighbors before buying. They checked me out while we were looking for our home. It's one of the (many) reasons we picked this area. We have awesome neighbors; every single one that I've seen on our street outside their houses, are people i would pick to be my neighbor, if they weren't already.

We'll be getting a new neighbor soon, as a house on the street is for sale. I hope they will consider us to be as good a neighbor to them, as all the other folks on our street have been to us.

Agreed! When were first shown the home we're now living in (purchased spring 2019) the TV sales robot said that if we're interested in this home he'd call in the office to see if it was available. We were then given an "opportunity!" for TV to "HOLD" it for us for 2 whole hours! We went out to lunch and made our decision quickly. We've all experienced that if we bought new from TV. What a learning curve for us! What a business model for them!

I first met the neighbors at the open house when I was walking through. They were all there chatting and were very friendly. Then, as we were checking out the mailboxes one of the neighbor’s asked for our email and we were invited to the monthly neighborhood social, which was the night before closing. While we were in escrow our neighbors threw a cocktail party for us and another couple who had just moved onto the street.

By the time we moved in we knew all the neighbors. They are great!

Makes sense to me. The neighbors would be as interested in the new comer as you would be in them. Are you social? Would you prefer to be left alone?