Living and working near London I always assumed the increased ethnic diversity and global outlook in the capital led to less racism. I assumed it was the rural homogenous countryside that had more endemic racism. I guess we all misunderstand each other all the time.
From https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-9477....
>In the short run, however, immigration and ethnic diversity tend to reduce social solidarity and social capital. New evidence from the US suggests that in ethnically diverse neighbourhoods residents of all races tend to ‘hunker down’. Trust (even of one's own race) is lower, altruism and community cooperation rarer, friends fewer.
There's plenty of secondary sources reporting on this study if you want to have a look for the varying opinions on it but I thought I'd link the source of it itself.
Whether less trust, less cohesion etc. == more racism is something I'm not in a position to draw a conclusion over, but it's interesting nonetheless.