social cohesion is gone in large part thanks to racial and cultural diversity. this has been studied again and again and the results are always the same, but you don't really need the studies because it's easy to see for yourself. when people share race, culture, religion, values, etc then they tend to care about each other more, even strangers that they assume are similar. neighbors help each other out and watch out for each other naturally, because the community feels more like an extended family than just random people who live nearby, like it is today. people just don't feel like they have anything in common with each other anymore, and usually find their social groups online instead of irl
United States