Whether it's a power walk, raised eyebrows or who walks through a door first, politicians like George W Bush and Tony Blair use a silent language to appear dominant and likeable.
Through gestures, mannerisms and facial expressions they can convey an impression of power, authority and fitness, psychologist and author Dr Peter Collett said yesterday.
But politicians can also unwittingly reveal if they are feeling vulnerable, uncomfortable and stressed.
In video clips shown at a science conference, Collett showed that Bush bites the inside of his mouth if he gets distressed while Blair raises his eyebrows when he is trying to look agreeable.
"The mouth bite shows that Bush is feeling nervous. It is what psychologists call emotional leakage," said Collett who used to work at the University of Oxford.
He added it is an unconscious reaction and was evident when Bush was told of the attacks on September 11, 2001 and on other occasions as his way of keeping his anxieties under control.
Raised eyebrows indicate submissiveness.
"Tony (Blair) often uses this in order to show he is agreeable and is attentive to what other people have to say and that he is not a threat to them," Collett told a news conference at the BA Festival of Science.
Blair also fiddles with the little finger of his left hand when he is stressed, puts his hands in his pockets when feeling vulnerable and often touches his stomach if he feels under attack, Collett added.
Touching one's stomach or the back of the head, which footballers often do when they miss a goal, is a regressive self-comfort gesture that originates from mothers doing the same thing to soothe their babies.
Bush uses a power walk, in which he swings his arms, to convey an impression of his masculinity, according to Collett.
Seemingly innocent things such as hand-shaking, the position of politicians on the red carpet and who goes through a door first can reveal much about political relationships.
While allowing someone to go through a door first is considered a sign of politeness, it can be a sign of power.
Gestures are also very telling in the relationship with Blair and his finance minister and presumed successor Gordon Brown.
"Brown looks incredibly uncomfortable when Blair has control and he is in the limelight," said Professor Geoffrey Beattie of the University of Manchester, who studies body language.
Collett said that during a Labour Party conference Brown displayed 322 signs of discomfort such as playing with his cufflinks and touching his face during a speech by Blair.
"Nobody can escape the eye of the psychologist," he added.