What does a handshake mean?
11 December 2013 Last updated at 10:39 GMT
If the most politically charged moment at the memorial service for Nelson Mandela was the booing of South Africa's President Jacob Zuma, the most internationally symbolic was the handshake between President Barack Obama and Cuban leader Raul Castro - Fidel's brother and successor. Or was it?
Newsnight's Jeremy Paxman considers what a handshake means - in under two minutes.