The Biology of Joy

Scientists are unlocking the secrets of pleasure—and discovering what poets already knew

Content Tools

Pleasure, like fire, is a natural force that from the beginning humans have sought to harness and subdue. We've always sensed that pleasure is somehow crucial to life, perhaps the only tangible payoff for its hardships. And yet many have discovered that unbridled pleasure can also be dangerous, even fatal. Since ancient times, philosophers and spiritual leaders have debated its worth and character, often comparing it unfavorably to its more stable sibling, happiness. No one, however, saint or libertine, has ever doubted which of the pair would be the better first date.

Happiness is a gift for making the most of life. Pleasure is born of the reckless impulse to forget life and give yourself to the moment. Happiness is partly an abstract thing, a moral condition, a social construct: The event most often associated with happiness, some researchers say, is seeing one's children grow up to be happy themselves. How nice. Pleasure, pure pleasure, is a biological reflex, a fleeting "reward" so hot and lovely you might sell your children to get it. Witness the lab rat pressing the pleasure bar until it collapses. Or the sad grin of the crack addict as the molecules of mountain shrub trip a burst of primal gratitude deep in a part of the human brain much like a rat's. Both know all too well that pleasure, uncaged, can eat you alive.

Some scientists claim they're close to knowing what pleasure is, biologically speaking. Their intent is to solve the riddle of pleasure much as an earlier generation unleashed the power of the atom. Splitting pleasure down to its very molecules will have many benefits, they say, including new therapies for treating drug abuse and mental illness. Others note that research on the biology of pleasure is part of a wider trend that's exploding old ideas about the human brain, if not the so-called "Western biomedical paradigm" in general, with its outmoded cleaving of body from mind.

The assumption is that somehow our lives will be better once this mystery has been unraveled. Beneath that is the enduring belief that we can conquer pleasure as we've conquered most everything else, that we can turn it into a docile beast and put it to work. That we've never been able to do so before, and yet keep trying, reveals a lot about who we are, as creatures of a particular age—and species.

Of all the animals that humans have sought to tame, pleasure most resembles the falcon in its tendency to revert to the wild. That's why we're often advised to keep it hooded. The Buddha warned that to seek pleasure is to chase a shadow; it only heightens the unavoidable pain of life, which has to be accepted. Nevertheless, most have chosen to discover that for themselves. The early Greek hedonists declared pleasure the ultimate good, then immediately began to hedge. Falling in love, for instance, wasn't really a pleasure, given the inevitable pain of falling out of it. The hedonists thought they could be masters of pleasure, not its slaves; yet their culture's literature is a chronicle of impetuous, often unspeakable pleasures to be indulged at any cost.

When the Christians crawled out of the catacombs to make Rome holy, they took revenge on pagan pleasure by sealing it in—then pretended for centuries not to hear its muffled protests. Eclipsed was the Rose Bowl brilliance of the Roman circus, where civic pleasure reached a level of brutal spectacle unmatched until the advent of Monday Night Football. Pleasure as a public function seemed to vanish.

The end of the Dark Ages began with the Italian poet Dante, who, for all his obsession with the pains of hell, endures as one of the great, if ambivalent, students of pleasure. His Inferno is but a portrait of the enjoyments of his day turned inside out, like a dirty sock. For every kind of illicit bliss possible in the light of the world above, Dante created a diabolically fitting punishment in his theme-park hell below. We can only guess what terrible eternity he has since devised for his countryman, the pleasure-loving Versace, felled in what Dante would have considered the worst of ways—abruptly, without a chance to confess his sins. At the very least he's doomed to wear Armani.

Dante's ability to find a certain glee in the suffering of others—not to mention in the act of writing—goes to the heart of the problem of pleasure. Let's face it: Pleasure has a way of getting twisted. Most people, most of the time, are content with simple pleasures: a walk on the beach, fine wine, roses, cuddling, that sort of thing. But pleasure can also be complicated, jaded, and sick. The darker aspects of pleasure surely lie dormant in many of us, like the minotaur in the heart of the labyrinth waiting for its yearly meal of pretty flesh. In the words of the Mongol ruler Genghis Khan, "Happiness lies in conquering one's enemies, in driving them in front of oneself and taking their property, and savoring their despair, and outraging their wives and daughters." He meant pleasure, of course, not happiness—but you tell him.

In the Age of Reason, the vain hope that humans could reason with pleasure returned. Thinkers like Jeremy Bentham took up the old Greek idea of devising a "calculus" of pleasure—complex equations for estimating what pleasure really is, in light of the pain often caused by the quest for it. But the would-be moral engineers, rational to a fault, found the masses oddly attached to the older idea of pleasure being a simple sum of parts, usually private parts. As for the foundlings thus multiplied, along with certain wretched venereal ills, well, who would have figured?

The first "scientists of mind" were pretty sure that the secrets of pleasure, and the emotions in general, lay locked beyond their reach, inside our heads. Throughout the 19th century, scientists could only speculate about the human brain and its role as "the organ of consciousness." Even more galling, the era's writers and poets clearly speculated so much better— especially those on drugs.

Two of them, Samuel Taylor Coleridge and Thomas De Quincey, both opium addicts, also may have been early explorers of the brain's inner geography. Images of a giant fountain gushing from a subterranean river in Coleridge's most famous poem—"Kubla Khan; or, A Vision in a Dream" bear an odd resemblance to modern models of brain function, especially brains steeped in mind-altering chemicals. Writing in The Human Brain (Basic Books, 1997), Susan A. Greenfield, professor of pharmacology at Oxford University, describes the "fountainlike" nerve-cell structures that arise in the brain stem and release various chemical messengers into the higher brain areas. As Greenfield notes, and Coleridge perhaps intuited, these geysers of emotion are "often the target of mood-modifying drugs."

De Quincey describes a similar terrain in  Confessions of an English Opium Eater (1821). He even suggests that the weird world he envisioned while he was on the drug might have been his own fevered brain projected, a notion he fears will seem "ludicrous to a medical man." Not so. Sherwin B. Nuland, National Book Award winner and clinical professor of surgery at Yale, expresses an updated version of that concept in The Wisdom of the Body (Knopf, 1997). In Nuland's view, we may possess an "awareness" distinct from rational thought, a kind of knowledge that rises up from our cells to "imprint itself" on how we interpret the world. "It is by this means that our lives . . . and even our culture come to be influenced by, and are the reflection of, the conflict that exists within cells," he writes.

Maybe De Quincey really could see his own brain. Maybe that's what many artists see. Think of Dante's downward-spiraling hell, or the minotaur in the labyrinth, even the cave paintings at Altamira and Lascaux. The first known labyrinth was built in Egypt nearly 4,000 years ago, a convoluted tomb for both a pharaoh's remains and those of the sacred crocodiles teeming in a nearby lake. It's an odd image to find rising up over and over from the mind's sunless sea, of subterranean passages leading ever deeper to an encounter with . . . the Beast. In an age when high-tech imaging devices can generate actual images of the brain at work, it's intriguing to think that artists ventured to the primordial core of that process long ago. And left us maps.

Today, Paul D. MacLean, National Institute of Mental Health scientist and author of The Triune Brain in Evolution (1990), describes a similar geography. He theorizes that the human brain is "three-brains-in-one," reflecting its "ancestral relationship to reptiles, early mammals, and recent mammals." Peter C. Whybrow, director of the Neuropsychiatric Institute at UCLA, uses this model to explain what he calls "the anatomical roots of emotion." Writing in A Mood Apart (Basic Books, 1997), his study of depression and other "afflictions of the self," Whybrow notes: "The behavior of human beings is more complicated than that of other animals . . . but nonetheless we share in common with many creatures such behaviors as sexual courtship, pleasure-seeking, aggression, and the defense of territory. Hence it is safe to conclude that the evolution of human behavior is, in part, reflected in the evolution and hierarchical development of other species."

Deciphering the code of art into the language of modern science took most of two centuries. One discipline after another tried to define what feelings like pleasure were, and from where they arose, only to fall short. Darwin could sense that emotions were important in his evolutionary scheme of things, but he was limited to describing how animals and humans expressed them on the outside, using their bodies, especially faces. William James, in a famous theory published in 1884, speculated that the brain only translates various sensations originating below the neck into what we think of as, say, joy and fear. Others saw it the other way around—emotions begin in the brain and the bodily reactions follow. Without knowing what pleasure actually is, Freud could see that the inability to feel it is a kind of disease, or at least a symptom, that he traced to (you guessed it) neurotic conflict.

By then, though, many people were fed up with all the talking. The study of mind had reached that point in the movie where the gung-ho types shove aside the hostage negotiator and shout, "We're going in." And with scalpels drawn, they did. In 1872, Camillo Golgi, a young doctor working at a "home for incurables" in an Italian village, discovered the basic component of brain tissue, the neuron. It's best not even to ponder how he got his samples. During the 1920s, German scientist Otto Loewi, working with frog hearts, first identified neurotransmitters: chemical messengers that carry information across the gap between the neurons—the synapse—to receptors on the other side. Meanwhile, the Canadian neurosurgeon Wilder Penfield, operating on conscious patients with severe epilepsy, managed to trigger various emotions and dreamlike memories by electrically stimulating their brains. Such work gave rise to the idea that various mental functions might be "localized" in particular brain areas.

In 1954, psychologists James Olds and Peter Milner made a remarkable breakthrough—by accident. While researching the alerting mechanism in rat brains, they inadvertently placed an electrode in what they soon identified as a rat's pleasure-and-reward center: the so-called limbic system deep inside the brain. When the rats were later wired in a way that let them press a lever and jolt themselves, they did so as many as 5,000 times an hour.

This became the basis for current research on the "biology of reward." Scientists like Kenneth Blum have linked what they call reward deficiency syndrome to various human behavioral disorders: alcoholism, drug abuse, smoking, compulsive eating, gambling. Blum traces these disorders to genetically derived flaws in the neurotransmitters and receptors now associated with pleasure, including the pathways tied to the brain chemicals serotonin and dopamine, and the endorphins. Other researchers aren't so sure.

We all know by now that endorphins are the "body's own natural morphine." The discovery of endorphins in the early '70s marked the start of what some have declared the golden age of modern neuroscience. The impact was clear from the beginning to Candace B. Pert, whose work as a young scientist was crucial to the discovery. A few years earlier, she had helped identify the receptors that the endorphins fit into, as a lock fits a key, thus popping the lid of pleasure. According to Pert, "it didn't matter if you were a lab rat, a First Lady, or a dope addict—everyone had the exact same mechanism in the brain for creating bliss and expanded consciousness." As she recounts in Molecules of Emotion (Scribner, 1997), her early success led to a career at the National Institute of Mental Health identifying other such messenger molecules, now known as neuropeptides.

Pert's interest in the natural opiates and their role in pleasure and pain soon took her into uncharted territory—sexual orgasm. Working with Nancy Ostrowski, a scientist "who had left behind her desire to become a nun and gone on instead to be become an expert on the brain mechanisms of animal sex," Pert turned her clinical gaze on the sexual cycle of hamsters. "Nancy would inject the animals with a radioactive opiate before copulation, and then, at various points in the cycle, decapitate them and remove the brains," Pert writes. "We found that blood endorphin levels increased by about 200 percent from the beginning to the end of the sex act." She doesn't say what happened to their own endorphin levels while they watched—but Dante has surely kept a log.

Modern students of pleasure and emotion have their differences. Pert, for instance, having worked so much with neuropeptides, doesn't buy the idea that emotions are localized in certain brain areas. "The hypothalamus, the limbic system, and the amygdala have all been proposed as the center of emotional expression," she writes. "Such traditional formulations view only the brain as important in emotional expressivity, and as such are, from the point of view of my own research, too limited. From my perspective, the emotions are what link body and mind into bodymind."

This apparent reunion of body and mind is, in one sense, Pert's most radical conjecture. And yet, oddly, it's the one idea that many modern researchers do seem to share, implicitly or otherwise, to varying degrees. Most would agree that the process of creating human consciousness is vastly complex. It is also a "wet" system informed and modulated by dozens of neurochemical messengers, perhaps many more, all moving at incredible speeds. Dare we call it a calculus? Not on your life. Any analogy of the brain that summons up a computer is definitely uncool. For now.

There also seems to be a shared sense, not always stated, that some sort of grand synthesis may be, oh, 20 minutes away. In other words, it's only a matter time before the knowledge of East and West is melded back into oneness, a theory that reunifies body and mind—and, as long we're at it, everything else. That may be. But given that a similar impulse seems so prevalent throughout the culture, could it be that what we're really seeing is not purely science, but a case of primal yearning, even wishful thinking? A generation of brilliant scientists, their sensibilities formed in the psychedelic '60s, could now be looking back to the mirage of mystical union they experienced, or at least heard about over and over again, in their youth. Perhaps they long to reach such a place, theoretical though it is, for the same reason a salmon swims to the placid pool where its life began. We, like all creatures, are driven by the hope of an ultimate reward, a pleasure that has no name, a pleasure that in fact may not be ours to feel. Thus we never conquer pleasure; pleasure conquers us. And for its own reasons, both wondrous and brutal.

None of which makes the alleged new paradigm any less real. As the poets of our day, for better or worse, the modern scientists of mind have already shaped our reality with their words and concepts. Who hasn't heard of the endorphin-driven runner's high, or traced a pang of lover's jealousy to their reptilian brain? On Star Trek Voyager, a medical man of the future waves his magic wand over a crew mate emerging from a trance and declares, "His neuropeptides have returned to normal!"

You didn't have to be a Darwin to see that the news gave Captain Janeway a certain . . . pleasure.