building demographics?

Snuffles, in rental buildings where I have lived for more than 15 years, you have two basic options which you described - either groups of people in their twenties or a mix of young families and older singles or couples. I much prefer the latter option. One way to ensure that you get the latter option is to look for buildings which require you sign a two year lease which weeds out many single people who do not want to make that length of commitment to an apartment. Another way is to hang out near the building entrance at times people leave/return from work or an evening out and see who lives in the building. You can also ask someone who lives in the building the demographic of that building - particularly if that person is unhappy living in the building, they will probably tell you the truth.

you can pick your spouse, but not your neighbors. Sounds like you should buy a house.

"you can pick your spouse, but not your neighbors. Sounds like you should buy a house."

Or even better yet, a co-op.

When renting, we found buildings that don't allow temporary walls were well-suited to weed out the just-out-of-college crowd and most families.

When buying, finding a co-op with almost all one-bedroom or one bedroom-plus-den apartments did the trick. Size of the place weeds out families; co-op board weeds out troublemakers.

Snuffles, I like how grumpy and misanthropic you sound. I like that you own it.

Excelsior!

If you don't want to live among lots of little kids, don't move to BPC.
lobster is right - do some legwork at buildings you might consider, to determine if the residents meet your criteria.

co-ops are worse... I lived in one - just because you think you can filter who lives there does not mean they aren't still assholes.

Good fences make good neighbors.