The last time you greeted someone, did you shake their hand? Now a harder question: what did you do with your hand afterwards? You probably didn't realise it at the time but the likelihood is that you subconsciously brought it up to your face and sniffed it! Using hidden cameras, Israel's Weizmann Institute researcher Idan Frumin has found that we humans do the socially more acceptable equivalent of what two dogs do when they first meet, as he explained to Chris Smith.
A transcript of this interview with Idan Frumin about people sniffing their fingers after shaking hands is available.