I'm from Britain, live in the US with my American wife, and find it hard to recognise these behaviours in anyone I've met who is younger than middle aged.
People here go from repressed up the wazoo to open and friendly as anything. Being in my early 20's, this is what I've seen all my life.
Claiming Britons don't like to be touched is wholly misleading as I hugged most of my friends, even my guy friends. Girls didn't avoid touching you. Put it this way, for a term of English origin, I had no clue what cooties was nor had I heard it mentioned growing up from anyone. It took me associating with Americans and Canadians to even hear the word.
On this topic, I've noticed that North America is seemingly the only country with a sociopathy over touch. Back in Yorkshire I remember getting served at bars and convenience stores and people would slap change into your hand frivolously. Here in Ontario there's this anal-retentive dance that people try to give you change but refuse to touch you to actually give you the damn change. They'll try to slot the note into your hand and drop the change from like 4 inches, it's psyco-level bizarre.
I guess this is the difference when you grow up in an area with a history of mining, fishing and farming. People aren't afraid of touch.
Yet somehow, nobody covers their mouth when they cough!
The only thing is Japan had two nuclear bombs dropped on it. Ontario has at most one outbreak of an infectious disease, which didn't really do a god damn thing; 44 Torontonians died from SARS... but by the average incidence of accidents over 5100 Torontonians literally died because 'shit happens'.
It's so completely bizarre to an outsider. I mean if this is a corollary to all North Americans, if I go to New York I expect everyone to duck and cower on the ground whenever they hear the sound of a plane. But they don't.
It varies hugely depending on context, even in London. For example my main group of friends in London is unusually tactile (for anywhere in the world). A kiss on the forehead, a slap on the arse, a hug for no particular reason in a completely asexual, gender- and orientation-nonspecific is completely normal[1]. There is no frickin' way I'd extrapolate from that to any other friends groups, let alone work colleagues, anywhere in the world.
[1] I have a theory that it's because we're all incredibly dysfunctional and run each other on the same code paths we'd use for cats.