Why We Love (20 page)

From Europe to Siberia, people also carved grotesquely buxom, faceless female fertility symbols out of stone, as well as realistic figurines of women they must have known. Hunters engraved the handles of ivory tools with graceful horses. And men and women bedecked themselves with beads, bracelets, and probably tattoos, as well as caps, headbands, and gowns. Wall paintings even suggest that women coiffed their hair.

Then by four thousand years ago, someone in ancient Sumeria wrote the first love letter ever found, inscribed in cuneiform on a fist-sized piece of clay. Today it sits in the Museum of the Ancient Orient in Istanbul, Turkey, a postcard from the past. This person loved. He or she felt the same rapture that lovers felt a million years before.

The Human Capacity to Love

I once believed that Skipper, Maria, Tia, and the rest of the animals who have become enamored of their mating partners feel the same sensations that you and I feel when we fall in love. I reasoned that as our ancestors got smarter, humanity simply embroidered this animal magnetism with a host of cultural traditions and beliefs. I have changed my mind. What convinced me that the human experience of romantic love is far more complex—and more intense—is the impressive brain architecture that generates our intellect and feelings.

“The brain is my second favorite organ,” Woody Allen reportedly joked. Had Woody thought carefully about the abilities of the human brain, he might have made it number one. We are so much smarter, so much funnier, so much more mechanically adept, artistic, spiritual, inventive, altruistic—and sexy—than any other animal that if you could somehow combine all the mental capacities of all nonhuman creatures, they would not equal the capabilities of a seven-year-old human child.

I think the mental equipment that produces these human talents also creates in humanity a
greater
capacity for romantic love.

To begin with, the higher primates have larger brains than most mammals, relative to body size. The human cerebral cortex (the outer rind with which we do our thinking and recognize our feelings) is almost
three times
bigger than that of the apes—gorillas, chimps, and orangutans.
21
The human brain is heavier, too. The chimp brain weighs about one pound while the human brain weighs three.
22
And size counts. Paul M. Thompson of the University of California, Los Angeles, has shown that the number of gray cells in the frontal lobes is significantly linked to intelligence.
23

The human brain is also more complex. The number of nerve connections between specific brain regions has increased significantly over that of the apes.
24
We even have more genes to build and maintain the brain. Humans have about thirty-three thousand genes. About one-third of them construct and sustain brain functions. And although we don’t have many more genes than apes, just a few hundred extra can make a qualitative difference in how the brain operates because genes interact—exponentially increasing the number of possible combinations. Known as the “combinatorial explosion,” at some point our forebears acquired a few more genes and thus
much
more machinery to build and operate an elaborate brain. Some of our genes even work faster than those of our closest kin.
25

Not only is the human brain generally bigger and more complex, but almost all of its specific regions have expanded.

For example, the prefrontal cortex, the collection of brain parts that reside directly behind your forehead, is twice as large as that of other primates (see diagram
here
).
26
It is more convoluted, too,
27
with a cortical folding that provides extra space for thinking. These regions are central to “general intelligence.”
28
Here we assemble facts, reason, weigh options, exercise forethought, generate insights, make decisions, solve problems, learn from experience, and plan ahead. We also add meaning and emotional value to our thoughts, assess our risks, and monitor the acquisition of rewards.

With this remarkable brain region, the prefrontal cortex, humans have infinitely more capacity to
think
about “him” or “her.”

Our human brains also enable us to
feel
intensely. Frankly, I have long thought that nature overdid it when it comes to human emotions. We “feel” too much. Now I know why. The human amygdala, an almond-shaped region on the side of the head beneath the cortex, is more than twice the size of the amygdala in apes.
29
This brain region plays a central role in generating fear, rage, aversion, and aggression; parts produce pleasure, too. With this brain capacity for generating strong, often violent emotions, we humans have the ability to link our drive to love with an enormous collection of feelings.

We are also uniquely endowed to
remember
“him” or “her.” “Memory, of all the powers of the mind, is the most delicate and frail,” wrote Ben Jonson. ’Tis true. Just try to memorize a long poem or remember what you ate a week ago today. To help us remember, however, nature contrived to make our hippocampus, the brain region we use to produce and store memories, almost twice as big as that of the great apes.
30
This brain region exquisitely recalls the feelings that accompany memories as well. With this remarkable factory and storage bin, the hippocampus, we humans are able to recollect the smallest details about “him” or “her.”

But of all the brain parts that evolved to intensify the experience of romance, undoubtedly the most important is the human caudate nucleus. As you may remember, the caudate became active as our lovesick subjects gazed at the photos of their beloveds. This brain region is associated with focussed attention and intense motivation to win rewards. And it is twice as large in humans as in our closest kin.
31
As the caudate enlarged among our
Homo erectus
ancestors, it may have intensified the urge to seek and win a sweetheart.

Exactly when a primitive form of animal magnetism finally evolved into human romantic love—with all its complex thoughts and feelings—no one knows. But many scientists now think that all parts of the human brain (except the cerebellum) expanded in unison.
32
We know when this began: some 2 million years ago. A million years ago,
Homo erectus
peoples had considerably larger brains. By 250,000 years ago, some of our
Homo sapien
ancestors had skulls as big as yours and mine. And by 35,000 years ago, their brains had taken our modern shape.

Humanity had emerged from its jungle crucible. Someday we may lift off from Earth entirely and soar toward the stars. These voyagers will carry in their heads exquisite mental machinery born on the grass of ancient Africa over a million years ago. Among these special talents will be our wit, our flair for poetry, the arts, and drama, a charitable spirit, and many other courting traits, including the astonishing human ability to fall head-over-heels in love.

Capricious Love

“But I am tied to very thee / By every thought I have; / thy face I only care to see, / Thy heart I only crave.”
33
In the mid-1600s, Sir Charles Sedley vividly expressed this intense drive to love another. But alas, this feeling isn’t always joyful.

As you know, romantic love does not necessarily go hand in hand with the urge to attach to a mating partner over a long period. You can fall in love with someone from a different walk of life whom you never wish to marry. And you can feel romantic passion for one person
while
you feel deeply attached to another, usually a spouse. Moreover, you can have sex with someone for whom you feel no romantic love, even feel romantic passion for one individual while you copulate with another. What madness—to be socially or sexually entwined with one person and wildly in love with someone else.

Why has the brain circuitry of romantic love become unlinked from feelings of lust and long-term attachment?

I think love’s capriciousness is part of nature’s plan. If a
Homo erectus
man had one wife and two children and meanwhile fell in love with a woman from a different band and secretly gave her two more young, he would double the number of his descendants. Likewise, an ancestral woman who was wedded to one man yet became entranced by another might bear her sweetheart’s baby and/or acquire extra food and protection for the children she had already borne. In short, the fickle brain circuitry for romantic love is capricious by nature’s design. It enabled our ancestors to follow
two complementary reproductive strategies in tandem.
Nariokotomi Boy and all his relatives could make a socially sanctioned mating relationship with one partner; with a clandestine lover, they could beget additional babies and/or acquire extra resources as well.

Today many men and women still pursue this dual reproductive strategy. The most recent statistics on American adultery come from a study done at the National Opinion Research Center in Chicago in 1994. Here scientists polled 3,432 Americans between the ages of eighteen and fifty-nine on many aspects of their sexuality.
34
One-fourth of these men and 15 percent of these women revealed that they had philandered during their marriage. Others may be lying, because many scientists think these figures are far too low.
35
American philanderers even have children by their clandestine partners. In a 1998 program to screen for genetic diseases, scientists were astonished to find that 10 percent of children tested were not the offspring of their legal fathers.
36

These adulterers are hardly unique. Philandering is common in all human societies on record.
37
“Cheating” is even common among other “socially monogamous” creatures.
38
In a study of 180 species of songbirds, some 90 percent of females bore some infants that were genetically unrelated to the “father” who fed them.
39
In fact, it has been said that the only truly monogamous creature in the state of California is a particular kind of vole.

We were built to love and love again. What joy this passion brings when you are single and starting out in life, divorced in middle age, or alone in your senior years. What confusion, what sorrow this chemistry can generate when you are married to someone you admire, then fall in love with someone else.

The independence of these emotion systems—lust, romantic attraction, and attachment—evolved among our ancestors to enable men and women to maintain several relationships at once. But this brain circuitry has created tremendous turmoil today—contributing to our worldwide patterns of adultery and divorce, the high incidence of sexual jealousy, stalking, and spousal battering, and the prevalence of homicide, suicide, and clinical depression associated with spurned passion.

Lost love. Almost everyone on earth knows the agony of rejection. Why do you plummet into despair when you lose somebody you adore?

7

Lost Love:
Rejection, Despair, and Rage

Lie still, lie still, my breaking heart;

My silent heart, lie still and break:

Life, and the world, and mine own self, are changed

For a dream’s sake.

Christina Rossetti

“Mirage”
1

“Walking inland, inland, inland, / I am walking inland. / Nobody loves me, she least of all, so I walk inland.”
2
An anonymous Inuit of the Arctic recited this sad poem in the 1890s.

Almost everyone in the world feels the agony of romantic rejection at some point in their lives. I have met only three people who claimed never to have been “dumped” by someone they adored. Two were men, one a woman. Both men were handsome, healthy, rich, and exceedingly successful in business. The woman was a young television star. These people are rare. Among college students at Case Western Reserve, 93 percent of both sexes reported that they had been spurned by someone they passionately loved. Ninety-five percent also said they had rejected someone who was deeply in love with them.
3
Almost no one in the world escapes the feelings of emptiness, hopelessness, fear, and fury that rejection can create.
4
“Parting is,” as Emily Dickinson wrote, “all we need to know of hell.”

Because my brain scanning colleagues and I wanted to understand the full range of romantic feelings, we embarked on a second project: scanning the brains of people who had recently been rejected by romantic partners. We found many volunteers; all were in excruciating psychological pain. In spite of their sorrow, perhaps because of it, they were willing to undergo fMRI testing. This experiment is in progress as I write, but the participants have already told me a great deal about this agony and the stages of despair the rejected lover must endure.

Poet Donald Yates once wrote, “People who are sensible about love are incapable of it.”
5
As you will see, few of us are sensible when it comes to rejected romantic passion. We aren’t built for it.

Rejected Lovers

“Have you just been rejected in love? But can’t let go?” My colleagues and I hung a flyer on the psychology bulletin board on the State University of New York at Stony Brook campus that began with these words. We were determined to scan the brains of men and women who had just been scorned in love. We sought only those who were really suffering.

Rejected sweethearts were quick to respond. As with our earlier experiment, we winnowed out those who were left-handed, had metal in their heads (such as braces on their teeth), were taking antidepressant medications, and/or were claustrophobic. Then I called the applicants and spoke to each at length, discussing the details of their unhappy love affairs and carefully explaining what would happen to them while in the brain scanner.