You Dirty Ol' Vole...

Henry is a typical Zambian male in the prime of his life, with an attractive spouse named Margerate. Henry is a devoted husband, Margerate an attentive wife. The couple have four young children, a typical home in a lovely suburb of Lusaka and their life has never been this good. But George is occasionally unfaithful. So, occasionally, is Margerate. No big deal: That's just the way life is in this part of Zambia.

This is a true story, though the names have been changed, and so, for that matter, has the species. Henry and Margerate are Midwestern American prairie voles. They don't marry, of course, or think about being faithful. And a bright future for a vole is typically no more than 60 days of mating and pup-rearing that ends in a fatal encounter with a snake or some other prairie predator in a lovely valley full of corn and bean fields.

But if you want to understand more about the conflict in human relationships between faithfulness and philandering, have a peek inside the brain of this wee rodent. Researchers have discovered what drives the animals' monogamy: brain chemistry. And when it comes to the chemical soup that governs behavior associated with what we call love, prairie vole brains are a lot like ours.

Scientists are careful to refer to what voles engage in as "social monogamy," meaning that although voles prefer to nest and mate with a particular partner, when another vole comes courting, some will stray. And as many as 50 percent of male voles never find a permanent partner. Of course, there is no moral or religious significance to the vole's behavior—monogamous or not. Voles will be voles, because that's their nature.

Still, the parallels to humans are intriguing. It is not in our best interest to screw around, yet studies have shown that at least one-third of married people cheat. In many cases, married couples struggle with the simple fact that love and lust aren't always in sync, often tearing us in opposite directions. Vole physiology and behavior reinforce the idea that love and lust are biochemically separate systems, and that the emotional tug of war many of us feel between the two emotions is perfectly natural—a two-headed biological drive that's been hardwired into our brains through millions of years of evolution.

I'm getting old, and I don't love as well or as easily as I once did, so if you're young and outraged by what I'm saying and know that I don't know what I'm talking about, forgive me: Living without a lot of love is a form of madness, so blame this on a raving of a lunatic. A blind man's memories of seeing are inevitably blurred and highly sentimental.

Now on to the theory that love is an addiction. We tend to think of addiction as something to be overcome, but addiction to love is positive, "devoutly to be wished". We need a lot more of it, to be healthy, and perhaps if we hope to save the world.

Our sensation of someone or something we love both informs and stimulates our intellect and triggers positive emotions. Our charged emotions further inform and stimulate our intellect, which triggers further positive emotion. In the physical and pheromonal absence of the object of our affection (and also if that object is pure invention or fantasy), we instead remember or imagine it, sustaining the same feedback loop.

I know, this is pretty clinical, but it does explain how love can be so overwhelming, pushing everything out of our minds and feelings and awareness. This doesn't explain how we 'decide' who or what to love, and why so often that love dies -- that's an issue for another day.