Sex and love are the great driving forces of human affairs: the source of our deepest feelings and the inspiration for much of our culture. Yet how much do we actually understand them?
Attraction. The very word attracts. Why should it not? Attraction is fantastically attractive. Especially when it is powerful and mutual. Attraction can provide a link to another human so irresistible that it feels like an enchantment, one that renders all other needs and duties oddly meaningless, tiresome and irrelevant.
Away from the object of desire, one is fretful and distracted, unable to eat, unable to sleep, unable to concentrate. All that matters is the next encounter, for with its consummation one will feel euphoric, blissful, thrumming with life and with tenderness. With that other person, one will feel that nothing is missing any more. Couples so drawn, talk of being two halves, complete only when they are together.
Who would refuse such luxury, such security and such communion? Who would not want to be so lucky? Anyway, isn't that passionate compulsion practically useful? Doesn't it encourage exclusive pair-bonding in humans, and foster the lovely notion that there's a perfect soul mate somewhere in the world for everyone? Or is that feeling so preposterously wonderful that, really, there has to be a catch somewhere?
Attraction, after all, can be so overwhelming of the individual, and of the individual's other necessary duties and relationships, that during most of Western history it has been considered dangerous and destabilising enough to be constrained as much as celebrated. The Greeks portrayed sexual attraction as a weapon, a dart that might pierce the flesh and possess a soul, causing chaos among humans and gods alike.
For Dante or Petrarch, courtly love was a kind of divine torture, with young men pining and fading for years at the sight of a chaperoned maiden who besotted them. The great literature of love Romeo and Juliet, Anna Karenina, Madame Bovary warns of the dangers of being driven by desire.
Even in Wagner's Tristan and Isolde, forbidden love leads to disaster and death. Except in this work, though, there is a sense that it was splendid, even sacred, nonetheless. Wagner contended that it was wrong, not right, to fight or fear erotic longing. His idea caught on, and plenty of people now subscribe to the belief that a truly significant passion should be gleefully accommodated, not resisted. Wagner's vision can credibly be argued as one which helped to dismantle views about attraction, desire and love that had for thousands of years been forged in the Judeo-Christian tradition.
That, sensibility, warned against being carried away by sexual passion, and portrayed such unbiddable emotions as an unreliable foundation on which to build anything as fragile as love, or nurture any creatures as vulnerable as children. By the second half of the 20th century, though, this culture of restraint had been jettisoned, and replaced by the idea that self-denial was self-abnegation.
Now, in its general thrust, our culture is in love with the idea of love, awash with cock-eyed romanticism and unable to tell any more what's attraction, what's lust and what's love. Puberty, and even childhood is suffused with a popular music soundtrack that peddles endless trite paeans to the central importance of modern romance. The most surprising of people want naff anthems celebrating some songwriter's long-since ruined "true love" at their weddings. At some point, most teenage girls at least flirt with the idea of giving attraction a dry run by developing a crush on a pop star. Heaven knows what Wagner would make of it all.
On the whole, people don't really like it when scientists tell them that attraction is all down to pheromones, or waist-to-hip proportion, or instinctive recognition of genetic differentiation. There's disgruntlement as well, when churchmen tell us that togetherness is tough work involving ceaseless dollops of selflessness and commitment to the needs of others. We don't like it when our mums tell us that it is not "real" because we have never met Frankie from Look We're Boys. It's love we want, because we want to believe that love conquers all.
It is considered a measure of the depth and the wonder of attraction, when a couple recognise a special bond from their first glance. Their eyes met across a crowded room. They fell in love at first sight. They knew they had found their soul mate. And so on. But really, it is not in the least surprising that many couples lay claim to such a moment of revelation.
The great thing about "love at first sight" is that it is retrospective. The exchange of a special look can be forgotten within moments if a seemingly perfect potential partner is exposed in a minute of conversation as a humourless bore, or a sleazy vulgarian, or merely myopic. But if the exchange of looks that register mutual interest is followed up by the discovery of easy conversation, shared humour, fascinating opinions, common enthusiasms, and a yearning to touch and be touched, then that first glance is remembered and treasured.
Even if the encounter goes nowhere even if one of the amazing things the two of you discover you have in common is a spouse at home looking after the children then that short time of togetherness can still be filed away as a beguiling monument to what might have been. And if the encounter does develop if sexual pairing is as intimate and intense as it promised to be, if care, commitment and domestic compatibility lead inexorably to the creation of one big happy family, then that first meeting becomes a talismanic opening to a family's narrative of perfect togetherness.
But social science does, in its controlled experiments and clinical assessments, offer an alternative story of love. Humans, like all other animals, tend at times to be in search of a mate. At such times, each encounter, with anyone who might possibly be considered a candidate, is an audition. Without even being particularly aware of it, people tend to size up potential partners and even just potential friends all the time. Research has shown that people make complex judgements about others based on age, physical appearance, sartorial presentation, deportment, demeanour and social context in a matter of seconds rather than minutes after seeing or meeting them. Our own observation of the world around us confirms that such triage can be ruthless.
People who are physically beautiful tend immediately to dismiss those they consider less beautiful than they are. People who reckon themselves stylish are repelled by a fashion faux-pas. People who set store by their social standing will, at a glance, decide whether a person is likely to be as privileged as them, and edit out those who don't measure up (so much so that they may find themselves unable to recall the colour of the hair of the waiter who served them all night, or notice that the same mini-cab driver picks them up all the time). When we are looking for a partner, we are auditing all the time. Once a target is so selected, the chances are that further investigation will indeed elicit mutual interest.
Despite all the myth and mystery the romance, if you will - that surrounds the process of human pairing, this, at bottom, is the essence of the matter. People tend to be attracted by people who find them or seem likely to find them attractive. The faces we like best are the faces that are looking our way. The eyes that we are mesmerised by are the eyes that are looking into ours.
The banal truth, around the world, is that couples tend to be homogeneous they choose (or in some cultures, have chosen for them) people who are at a similar level to them of attractiveness, or intelligence, or background, or economic power. When people step outside that convention, others are often distrustful of the couple in question and their motives.
A beautiful young woman, for example, may decide that she is not going to barter her beauty and youth in the sexual marketplace in order to snare someone who is as young and beautiful as she is. She may decide instead that she'll cash in nature's chips for old and rich. It's a fair exchange between consenting adults, but one that's seen as pretty risible.
We may be fascinated when people make truly surprising or weird love matches like the upper-class Englishwoman who marries a traditional Inuit and lives happily ever after. But mostly we are fairly disapproving when people break the unwritten rules of the mating game and use the advantage of their sexual attractiveness, or their money and power, to pull someone who is, in that telling phrase, "out of their league".
So, can the ghastly truth be that those treasured coups de foudre (love at first sight)- those towering edifices built on the magnetic rock of primal, perfect love, occur when a person instantly identifies, or thinks they identify, nothing more or less than a suitably flattering reflection of themselves? Can overwhelming attraction, whether or not it develops into anything that endures, actually be at root narcissistic?
Anecdotal reference to that heady feeling of novel attraction, enthusiastically returned, will confirm that along with the weak knees, fluttery tummies and bonkers attachment to the essential truth of the silliest song lyrics, a keenly enjoyable aspect of the matter is the bolstering of one's own ego. Part of the joy of having that other person so intimately present in one's life is firmly connected to the undeniable fact that they also make you feel just great about yourself.
The ruminations on attraction that have been offered since Wagner's day by psychoanalysts and psychiatrists are often little more welcome than those of the scientists who say that your partner is not perfect for you because you mutually deserve such a marvellous mate, but because you just have smells that trigger each other's hormones.
Freud placed the ability to form meaningful relationships with the opposite sex as the result of good parenting, and the inability to do so as a consequence of dysfunctional relationships between girls and their fathers or boys and their mothers. He also suggested that while a degree of narcissism was present in all humans, it was important to release self-love by giving love to another person, or else narcissism would grow unchecked and become destructive.
Jung went further, and suggested that what seemed like "love at first sight" was merely projection. People see their masculine animus or their feminine anima in a member of the opposite sex, and are attracted by what they recognise as the unconscious and hidden part of themselves. For Jung, it was important to understand that aspect of one's psyche, so that one could stop projecting, grow up (or as he called it, individuate) and learn to engage with one's anima or animus so that one could choose wisely and start forming adult relationships.
The inability to "individuate" was for Jung the reason why people sometimes found themselves trapped in a romantic groundhog day, choosing again and again similarly unsuitable or abusive partners, and falling into unreasoning obsessions ending in hurt and tears. Again, such an analysis is not always entirely welcome, and it does indeed seem like rather a con the idea that the "unlucky in love" ought to sign up with a Jungian analyst and work on getting to know and understand their hidden sexual archetype. Yet like many of Jung's ideas and many of Freud's it is hard to dismiss completely.
Anthony Storr, a renowned psychiatrist of a more practical bent, once remarked that if people could get a grip on their tendency to form neurotic attachments to those who displayed the most destructive traits of a parent, then his consulting rooms would be empty. Which, in the end, is another way of saying that whatever we might tell ourselves about coups de foudres and love at first sight and irresistible passion we fancy the people that our genes and our upbringing tell us to.
But where's the romance in that?