Perhaps you’re seeing some implied slight against the US where there was none? Neither of the people who pointed out the pretty indisputable fact that Europe is a culturally diverse place did so in a way that implied that the US isn’t.
Never mind. The point has already been made, and more politely.
That difference is roughly comparable to the difference between Edinburgh and Glasgow, and is smaller than the difference between the Flemish and Walloon regions of Belgium. You probably think that countries in Europe have a uniform culture similar to that within states in the US: there can be more diversity within one country in Europe than there is across the whole United States.
I think that is a bit different than trying to compare Norwegians, Georgians, Cypriots, Russians and Swiss (plus all the others). How much does the average Turk living on he European side of Istanbul have in common with a typical resident of the Faroe Islands?.. much less than the average Hawaiian and New Yorker.
How about the Cajun living in the bayous of Louisiana vs. the typical resident of Malibu, California. You don’t know much about the US.
I have traveled all across Europe, the cultural distinctions in Europe are no more varied across many cross sections of the U.S. Been out of Ohio, lately?
You are ignorant of the very diverse cross sections of America, if you believe it is undisputable.
It’s clear to me this thread should be IMHO, anyway. There’s no factual answer to this question, in as such without a scientific study to have occurred.
It varies here from town to town, country to city, street to street. Typically if the area has a lot of kids of the same age growing up together the families can’t but get to know each other and become friendly. A lot of commuter areas, or streets with different demographics are largely anonymous. My neighbours are all friendly with me but I’ve only ever set foot in one of their homes for about 2 minutes. Only one of them has ever been in our home. My “neighbourhood” is nearly as much the other people who work in stores in the town, we nod, say hello, do favours, shoot the shit etc.
There have been three sets of neighbours here since the house was built in 1951. I believe my father was friends with the first ones (who emigrated), we hated the second ones, (who were scum), and are largely indifferent to the present ones, who have been here for about thirty-five years. We say hello if you see them in the street, but that’s about all, unless some emergency compels us to combine forces on something. He cleans the windows, which is his living. I don’t know what she does. Their children were a pain growing up, but they’re long gone now. On the whole they’re not a problem, they mind their business and we mind ours, and that’s they way we like it. Now he is moving East, and someone else will live there 
The first house I grew up in (in Saskatoon, Canada), my parents were fairly close friends with a bunch of neighbours who all had kids our age (e.g. up to age 7, say). Then we moved to another house where we had the “nodding acquaintance” relationship with the neighbours.
My cousin is living in Halifax, and she says her friendly neighbours invite themselves over pretty much whenever they want. 
So I don’t think you can judge too much based on climate.
I believe Desert Nomad is an American.
Your points are highly questionable. I’m American; I grew up in California, and I’ve lived in the Midwest for the last several years. I’ve also lived in Eastern Europe, and traveled quite a bit in Western Europe. The idea that Americans are as culturally diverse, from a regional standpoint (ie, comparing the overall culture of one region to another) is, to me, laughable. My area in Bulgaria is roughly 60% Orthodox Christian and 40% Muslim. The major languages in the area are Bulgarian, Turkish, and Romany. People’s idea of a nice meal is yogurt cucumber soup, stuffed peppers, and kebab, with a glass of rakia. Many people are unemployed, as local factories had closed following the fall of communism. In the fall, people make rakia and wine in their backyards from their summer grapes, and jam from the cherries in their yard. If you want to try sample your neighbor’s wine or rakia, it’s no big, just let yourself into their house. Make sure to bring an odd number of flowers as a gift.
Hey, Western Europeans, does any of this sound like where you live?
Anyway, in my village in Europe, sure, you could ask your neighbor for anything. Everyone knows each other.
Israel (not Europe, of course), very true. You yourself (if you’re a Jew and not an asshole) can get passed around like a cigarette in a trench throughout the country.
And that a 4K town is not the same as a 40-people village or the same as a 4M city, no matter what continent or country they happen to be in?
I’m slightly baffled by your logic. I said that it is indisputable that Europe is a diverse place. What does diversity in America have to do with that claim?
It’s like someone says “the sky is blue” and you say “you are ignorant of the colour of grass. It is clearly green.”
When I was growing up, my family was friends with most of the neighbors. Doing things for one another, stopping by for barbecues, us kids going to babysit their kids, etc. A lot of that had to do with the fact that my mom was a SAHM and had more time to talk to the other stay at home moms, or check up on the retired folk, or be the emergency call person for a working neighbor’s kid, etc.
I live in a similar suburban neighborhood now and am passing friendly with a few but only “borrow stuff, watch the house, do things with” friendly with one.
I’ve lived in a suburb-esque locale and, with only one or two exceptions, we didn’t know any of our neighbors. At all. We didn’t even nod to them and they didn’t even nod back.
That being said, I was raised in the 90s and 00s. But I’ve never even known people who were like that in their neighborhoods. Maybe the issue has more to do with eras and not with location.
He just said that saying Europe has diverse cultures emphatically does not imply that the US isn’t diverse. It is pretty much indisputable that Europe is diverse’. Language, culture, traditions, history, it’s all vastly different over the country. But again, mind blowing as it is that I have to repeat it, that doesn’t mean the US isn’t also diverse. It is, and that is also indisputable. Though people in the US do have a lot more in common with each other, the question might be - do they all behave the same way with people next door? I would posit that they do not, since as you insist on pointing out, they are a diverse people too.
So I suppose it all depends on where in Europe (and specifically perhaps, where in each country in Europe) and where in the US are you talking about.
I haven’t come across it so much in towns or cities, but certainly rural villages in northern England still very much have a ‘community’ in as much as pretty much the whole populace knows each other and regularly socialises together; greatly facilitated by the Great British tradition of the village pub, although not restricted to drinking together.
My grandparents live in such a village, and when weather permits, most doors and windows are left wide open no matter the time of day or night, and regardless of whether anyone happens to be home. It’s not uncommon to be sitting with my grandparents and hear the shout of a neighbour letting themselves in, “Only me! I’ll put the kettle on shall I?” without necessarily having come to beg, borrow or return anything.
I remember a few years ago my dad tried to convince my granddad that leaving doors unlocked when you weren’t in wasn’t that great an idea, that times have changed and such. He just got told “Any tea-leaf wi’ ‘alf an ounce o’ common sense can si’ there’s nowt worth pinching frea these houses! Besides, what if (fellow from over the road) runs out a’ 'bacca and I’m not in?”, and refused to discuss it further.
This is completely at odds with the neighbourhood I live in, we say hello to the neighbours on one side because our driveways are alongside each other, but I’ve yet to even see the residents of the house on the other side in the 6 months we’ve lived here.
When I was a kid, growing up in the Home Counties, we knew most of the people in our street or at least the ones who had kids. It was quite common for the kids to all be off playing somewhere with only one parent knowing for certain where we all were. The neighbours used to babysit and petsit frequently, and it did feel much more like a community that my current street.
I am on speaking terms with the guy who lives next door but one, because of the peculiary arrangement of our property boundaries - I need to speak to him sometimes as our drainage access is technically on his property, and if I need someone to look at the guttering or pipes on one side of the house, they need to get access via his driveway which has locked gates on it.
Aside from that, I know none of the other residents. The neighbours on the other side of our house are renters and they are, I believe, Nigerian. I do know the landlord as, again, he keeps us informed of work being done on his house in case he needs to (for instance) get onto his outhouse roof by putting a ladder on our side of the fence.
The rest of the folks on the street? Well, most of them are immigrants and don’t speak English. How do I know? I’ve done some door-to-door canvassing and I know that virtually nobody actually understood what I was saying to them. They keep themselves to themselves, especially after a few incidents when we found there were groups from ‘rival’ Eastern European ethnic and religous groups, and they pretty much had a riot down the street when they realised where their neighbours were from.