We begin with the most primal signal of all - sexual attraction. Whether we like at it not, when we look at a face, we look at its symmetry - the key, claims Professor Randy Thornhill of the University of New Mexico, to what we call beauty. But there's more to symmetry than meets the eye. But our faces equip us for more than just sex. We arrive into the world with an enormous repertoire of facial expressions.
Babies recognise the parental face in the first few weeks of life.
They engage their mothers with a set of expressions designed to please. Perhaps the most astounding feature of the human face is its ability to convey emotions. Most basic facial expressions transcend ethnic boundaries. We discover why that happens and the fascinating story of how we're able to conceal, hoodwink and manipulate our emotions through our face - and the times when we're simply incapable of maintaining control. We'll meet Matthew Joffe, a native New Yorker who, from birth, has been unable to move a muscle in his face.