On my three visits to the US (all to Florida) I noticed this peculiarity.

In the UK, the rule is to place maximum posible distance between yourself or your group and anyone else in the area. A British family, even with crying children and/or weary elders, will walk an extra two or three hundred yards to find an empty bench rather than sit down on an already occupied one. If they spot one that is the middle of three empty ones, they will go even further to secure it.

An American in search of a seat will plonk themselves down on the first one that has a space, whether or not it is already occupied.

For the English, if one is forced to share a bench with a stranger, the etiquette is to angle ones' body away from them, never make eye contact and under no circumstances utter a word to them.

Americans will no sooner have setteld than they will introduce themselves, and within ten minutes, you will know their given name, where they come from, what they do for a living, and a hundred other things which no English person would dream of telling a stranger or even someone they've seen every day for ten years!

Americans tend to stand much closer than we are comfortable with.

Americans have apparently never 'heard them talk'. As in "No, dear, you may not plasy with those children. I've heard them talk and they're from Liverpool/London/Birmingham (insert place of choice)."

Strange people!