Harvard phychologist Nancy Etcoff observes that, with this vital equation very much in mind, our brains behave like a highly sensitive radar constantly hunting a signal. If we're shown the photograph of a face, it takes us less than a fifth of a second to make a judgement of its beauty.

Much of the language of this energy is hard-wired and universal. Even three month-old babies have been shown to prefer gazing at conventionally beautiful faces, and adults from diverse ethnic cultures can all agree on who is exactly how good-looking in other populations.

Experimental studies have also established that the active ingredients include symmetry, order, proportion and balance. Since beauty is so powerful and important, we can be thankful that there are many ways to be beautiful, and very many sources. And though we most readily think of experiencing that energy through our five physical senses of sight, sound, taste, touch and smell, other dimensions are even more potent. For example, there is movement-which can be the internal, kinaesthetic sense of our own bodies in dance or sport; or the thrill of seeing an art or craft well performed. Consider, too, how ideas, insights, and solutions, can be deemed beautiful. Among scientists, Einstein's Theory of Relativity is unanimously praised for its extraordinary beauty.

Yale's David Gelernter, a professor of computer science, has argued convincingly that "lust for beauty" has driven the great technological discoveries. It is no accient, he would claim, that Mitchell's Spitfire, with its Merlin engines and distinctive wings, could help win a war while also seeming wonderful to the eye and ear.

And just as the plan for a bank robbery, a bridge, or a computer program can all work beautifully, so can a whole personality. We know from the studies of many lifetimes that humans find a balance of loving and confidence and kindness and humour to be highly attractive and very healthy qualities.