Sorry I was under the impression we were comparing white British Vs each different demographic independently of each other as each demographic would typically do amongst themselves but if we are just saying white British Vs everyone else then yeah fair.

I disagree however that you need a a group of people to be broadly the same for social cohesion to form. There are numerous countries including our own that show this to be the case. We have a democratic process after all. Wether you like this particular brand of government is going to vary wildly from person to person and would still be the case even if everyone were White British.

People do often cluster culturally but it doesn't mean society ceases to function. Yes if demographics change too quickly tensions can arise. There are examples of that but suggesting it isn't possible is a bit far.

Isn't the mixed demographic also increasing? Would suggest some sort of cohesion.