Developing intercultural communicative skills

Thumb gestures in the UK and USA
Both Brits and Americans use thumbs up to mean OK, but with the British being less enthusiastic users and generally only giving two thumbs up ironically or to provide moral support for someone who thinks that they are failing. A thumb up to hitch a ride is also the same in both places. In baseball a thumb moved towards your shoulder means “You’re out”, something that is occasionally used outside sport with similar meanings in the USA.
The A-OK gesture in the UK and USA
Both Brits and Americans understand a circle made with the index finger and thumb with the other fingers raised to mean “okay”, but until I did the PADI diving course I don’t think I had ever actually made that gesture. It still seems quite American to me, and I use thumbs up much more commonly. Unlike many other countries, this is never an offensive gesture for English speakers.
Number and intensity of gestures in British and American English
The British are famous among Europeans for using few gestures, and guides to the UK for foreigners often warn them that wild waving of arms around is taken to be a sign of mental instability such as megalomania and/ or trying to hide a weak argument. However, by international standards you could probably say the same thing about Americans. While Americans tend to be more expressive than Brits in situations such as TED talks, they still tend to limit most movement to gestures with specific meanings such as the ones described in this article. A couple of my physics lecturers seemed to go the opposite way when trying to make a boring lecture seem interesting, producing strange random gestures that don’t match what they are saying, something which I haven’t seen American speakers do.
Fist bumping in the UK and USA
Although fist bumping (touching fists with someone instead of a high five or handshake) has been fairly common in the UK for a while, it is still seen as an American thing to do and so is often done with at least a slight ironic smile, and older people might even not reciprocate.