“There’s no art to find the mind’s construction in the face,” wrote Shakespeare. Present-day scholars would disagree. Desmond Morris’s classic People Watching, Albert Mehrabian’s widely discussed Silent Messages and Paul Ekman’s extremely influential Emotions Revealed all suggest that our body language affords a fundamental glimpse into our thought processes. Stances, gait, facial expressions and hand gestures in the species Homo sapiens each tell their own fascinating story. Today, there’s a burgeoning global industry devoted to decoding the tell-tale signs of emotional attitude, especially where public figures are concerned. Consider, for instance, the media attention showered on Michelle Obama’s on-camera eye-roll at a bipartisan congressional lunch earlier this year. Interpretations of this single ocular act ranged from suggestions that the American First Lady had bad table manners to assertions that she was sceptical, distracted, amused, disgusted or surprised. Another recent furore involved Bill Gates’s one-handed handshake with the South Korean prime minister, his left hand casually resting in his pocket. Was Gates being disrespectful or just being himself? Was this a clash between Asian and western values or merely much ado about nothing?