It was ‘the bump that shook the world’. An innocent gentle knuckle-touch between Barack and Michelle Obama one Tuesday night in early June 2008. Mr Obama had just claimed victory in the Democratic presidential nomination and in the euphoria on the stage in St Paul, Minnesota, the two daintily knocked knuckles in front of the world media.

Soon the whole world knew what a ‘fist bump’ was. From the States to South Africa, from Sydney to Stockholm, the gesture was front page news.

Newspapers and magazines published whole features about the gesture. Time magazine presented ‘A Brief History of the Fist Bump’. The British Guardian went so far as to compiling an entire picture gallery showing that not only African Americans do it (the Obamas, Tiger Woods, Will Smith); not only white Americans do it (Tom Cruise); but even the Dalai Lama and Prince Charles do it!

The fist bump, known by dozens of other names ranging from ‘bones’ and ‘pound’ to ‘respect’ and ‘knudge’, is thought to have originated in the late 1960s or early 1970s, and was, until that memorable Tuesday, usually associated with sporting events and beer commercials, and chiefly practised among African Americans (presumably until Tibetan Holinesses and British Royalty knuckled down to it).

It is interesting to note that the central role in this gentle and friendly greeting is played by the clenched fist – normally seen as a sign of hostility and perhaps violence.