My impression of Paris is that they are pretty misanthropic in general. We were actually appalled at the people there. Just utterly rude in all facets. Snobs, have no qualms staring at you, pretend to not speak a word of English when you know they do.
At one restaurant they just pretended we weren't there, I guess we hadn't met their dresscode, but rather than telling us that, they just completely ignored us.
At another restaurant, a couple at a nearby table stared at us the entire meal. Not just a glance here and there, but they were physically turned around in their seats and pointing at us. It was awful.
I don't think Londoners are particularly nice, warm or friendly, but they are almost always polite (except when driving). You get used to it and forget the world isn't like this.
(of course, not everyone in Paris is like that. It's just a very different feel from London, the general code of politeness doesn't seem to hold).