While Americans have a reputation for being brash, direct, and not shy about sharing their feelings, the opposite can be said for the majority of Brits.
Of course, you can’t apply generalizations to all inhabitants of any country. But I’ve found that many Brits value having a stiff upper lip, a finding mirrored by a BBC survey. My partner is a perfect example of this — she tends to bottle up her emotions rather than talking about them because she prefers to just get on with things without complaining.
Rather than processing events in depth, many Brits would rather just brush things under the carpet and keep their opinions largely to themselves. Not following suit can be considered rude and obnoxious, two qualities I’ve heard Brits ascribe to Americans.
That being said, I’ve found that many Brits appreciate American candor and find it charming — like most things, it depends on the person.