Exuberance: The Passion for Life (20 page)

Full-throated and contagious laughter probably evolved after our early ancestors scrambled down from their trees in a search for new habitats. Having left their arboreal territories, they required more sophisticated and closer social ties with one another, and faster means of communication; they needed, above all, to cooperate. Smiling and laughter, which in all likelihood evolved as more distinct, less mistakable forms of primate play-grins and play-faces, enabled faster communication across longer distances and
helped forge stronger, more obligatory social bonds. The increase in physiological arousal and motor activity intrinsic to laughter made the communication of positive emotional states both more accurate and more difficult to resist. Exuberant laughter is nothing if not hard to ignore and difficult to feign. The ethologists Jan van Hooff, of the University of Utrecht, and Signe Preuschoft, of the Yerkes Primate Lab at Emory University, believe that
smiling and laughter had very different origins—smiling as a way to signal nonaggression, laughter in the context of joyful play—and argue that the more hierarchical the primate society, the more unambiguous the display had to be in order to signal a playful release from the usual social status.

The powerful social ties initiated or shored up by laughter would have been vital to early hominids in creating the cooperative behaviors necessary to explore new lands, to hunt, and to raise young together; it would have been critical, as well, to generate the trust necessary to take risks as a group. Laughter, then as now, would have helped to disarm tension and to ameliorate stress and loneliness. It would have prompted closeness: bonded mother to infant, mate to mate, and friend to friend. (Indeed, Rupert Brooke observed nearly a hundred years ago that laughter is “
learnt of friends”; and it is in the context of friendship that laughter is most warmly shared: “
From quiet homes and first beginning, / Out to the undiscovered ends,” wrote Hilaire Belloc, “There’s nothing worth the wear of winning, / But laughter and the love of friends.”) Laughter, millennia ago as now, would have helped veil the terrors of life. It would have bound individuals to their communities, and its infectiousness—fast sent among its members, body to body, brain to brain—would have allowed the group to respond en masse, not just as individuals, one at a time and disjointedly. Laughter gives rise to yet more laughter and sends out, as it does, well-being to the far corners; it spreads its delights far, fast, and furious.

On occasion, laughter spirals out of control.
Epidemics of contagious laughter have been documented by the University of Maryland neuroscientist Robert Provine. One, which he describes in his book
Laughter: A Scientific Investigation
, started in 1962 in Tanganyika, in a mission-run boarding school for girls between the ages of twelve and eighteen. Three girls started laughing. Uncontrollable laughter, crying, and agitation quickly spread to 95 of the 159 students (no teacher was affected). The school was forced to close a month and a half later; it reopened, briefly, but then had to close again after 57 girls were stricken. Before finally abating two and a half years later, Provine writes, “
this plague of laughter spread through villages ‘like a prairie fire,’ forcing the temporary closing of more than 14 schools and afflicting about 1,000 people in tribes bordering Lake Victoria in Tanganyika and Uganda. Quarantine of infected villages was the only means of blocking the epidemic’s advance.… The epidemic grew in a predictable pattern, first affecting adolescent females at the Christian schools, then spreading to mothers and female relatives but not fathers.… The laughter spread along the lines of tribal, family and peer affiliation, with females being maximally affected. The greater the relatedness between the victim and witness of a laugh attack, the more likely the witness would be infected.”

Research supports the proposition that laughter has gender-specific aspects.
Women laugh more often than men, although men are more likely to evoke laughter in others. Both men and women are far more likely to laugh in the presence of others than when they are alone. This is true, as well, for
chimpanzees and college students. In one study of seventy-two undergraduates, psychologists found that
students were thirty times more likely to laugh when they were with others than when by themselves.

Contagious laughter is put into service as “new wine” in some Pentecostal revival meetings. One minister, who deliberately
induces spreading waves of laughter in his congregants, encourages his followers to let the “
Niagara of laughter … bubble out of your belly like a river of living water.” The “new wine” analogy is apt: laughter causes the release of opiatelike chemicals in the brain; this in turn creates a sense of intense, if transient, well-being.
The long-term physical benefits of laughter—increased longevity and immunity, lowered blood pressure—are widely cited but not clearly documented. It is likely, as Provine points out, that at least some of the physical benefits of laughter come about from the advantages conferred by enhanced social bonding.

The biology of laughter is only partially understood. As with so much else that bears relation to exuberance, temperament is involved:
extraverts laugh more often and more intensely than introverts. Genetics also plays a role in proneness to laughter. Rat pups, for instance, when tickled on their ribs and bellies respond with a chirping “play vocalization.”
Rats that chirp the most also play the most; they are also the most eager to be tickled. When scientists interbreed the “chirpiest” rats, they find, four generations of rat later, that the selectively bred young rats chirp twice as often as their great-grandparents.

The physical mechanisms of laughter seem to originate in ancient parts of the brain, but the cortex is involved as well. The stimulation of “pleasure centers” in the brain triggers laughter.
Brain scans taken while experimental subjects are listening to jokes show activation in the nucleus accumbens, the same area of the brain that is involved in reward-related behaviors. (Conversely, brain imaging studies show that particularly humorless people are more likely to have damage in that particular part of the prefrontal cortex.)
The funnier the joke, researchers find, the more brightly the reward circuitry lights up.
Scientists believe that the reward for “getting the joke” is one of evolution’s ways of getting our species to exercise and expand more diverse and sophisticated neural pathways.
Nonobvious connections are at the quick of wit and social humor; predictability dampens both. We laugh to keep our minds agile and to keep our ties to others fresh and resilient. We laugh because laughter returns us with pleasure to our common humanity; it recommits us to the cooperative roots that sprang into being as we moved from tree to savannah. We need these roots now as we needed them then.

Exuberance attracts and then bonds animal to animal; in doing so, it helps create the emotional ties necessary not only for communities to thrive but for potential breeding pairs to commit genes and energy to mate, reproduce, and raise young together. In the animal world, flamboyant mating dances and the vivid colors and energetic, extravagant rituals of sexual displays are an important part of the excitation of sight, smell, and hearing that attracts sexual partners. We are but one of many of nature’s manifold species to first lure a mate with exuberant promise and then engage joy to further entwine us. Cole Porter wrote of this, unforgettably: “
Cold Cape Cod clams, against their wish, do it.…/ In shallow shoals, English soles do it, / Moths, in your rugs, do it”; and, Porter continued, with an image for the ages: “Old sloths who hang down from twigs do it.” They all do it, he said, they all fall in love. But it is among our own species—not among moths or sloths—that love is so endlessly celebrated.

Exuberance and passion are critical during the early stages of love, for it is then that an intoxicating attraction must occur, a potential mate must be pursued, and a relationship must be intensely, if not recklessly, explored. “
Hot blood begets hot thoughts,” wrote Shakespeare, “and hot thoughts beget hot deeds, and hot deeds is love.” Passion rides roughshod over hesitating judgment; it dissolves inhibitions. Joy incites a catnip rapture; it provokes play and exploration of another’s world. Early love, declared Martin Luther, is “fervid and drunken, blinds us and leads
us on.” Four hundred years later, Thomas Hardy said much the same thing: “
Yea, to such rashness, ratheness, rareness, ripeness, richness,” he wrote, “Love lures life on.”

Exuberant love is addictive; it excites and infects, and it sends those who experience it out on a quest for more of the same. It not only lures and binds, it teaches. It instructs in the rewards and perils of sex and metes out pleasure for engaging in behavior that perpetuates the species. Love awakens and refreshens. “
The simple accident of falling in love,” said Robert Louis Stevenson, “is as beneficial as it is astonishing. It arrests the petrifying influence of years, disproves cold-blooded and cynical conclusions, and awakens dormant sensibilities.” Love also vouchsafes a time of discovery—of play and expansiveness, of incrementally deepening intimacy—before a more permanent commitment to a partner has to be made.

Exuberant love transforms those swept up in it; it “
sets the whole world to a new tune,” as William James put it. Things not heard before, emotions not felt before, all come into the lover’s field of experience. When the smitten sailor in Gilbert and Sullivan’s
H.M.S. Pinafore
sings that only
Love had been his tutor, anyone who has been in love instinctively understands. We may or may not learn wisely from love, but we certainly learn. And by our experience we are bound more closely to those who likewise are communicant with the lessons and lure of love.

Romantic love usually settles into a less passionate but more stable relationship. This is an attachment sustained in good measure because of our wiring; pleasure and affinity circuitries wend together in our brains. Receptors for oxytocin, a mammalian neuropeptide that facilitates attachment and social learning, mingle with dopamine receptors in the nucleus accumbens, an area of the brain we have seen to be intimately linked to seeking out and experiencing pleasure.
This marriage of affinity and joy is one we share
with another unusually monogamous and social mammal—an animal overlooked by Cole Porter, but not by neuroscientists—the prairie vole. This tiny mouselike herbivore pairs for life (which, admittedly, is a fleeting one). As with humans, its oxytocin and dopamine receptors overlap in the nucleus accumbens.
When a chemical that blocks oxytocin receptors is injected into the brain of a prairie vole, the animal’s typical pair-bonding is replaced by indiscriminate mating behavior. In contrast, the behavior of the montane vole, a meadow mouse that does not establish lasting pair bonds, is more consistent with the approximately 95 percent of
mammal species that are not monogamous.
Examination of the montane vole’s brain by Tom Insel, now director of the National Institute of Mental Health, and his colleagues at Emory University revealed that oxytocin and dopamine receptors are not in the same close proximity as they are in prairie voles.

Exuberant behavior and emotions—whether displayed in love, manifest in laughter and play, or kindled by music, dance, and celebration—have in common high mood and energy. They act on the same reward centers in the brain as food, sex, and addictive drugs, and they create states of mental and physical playfulness. Indeed, brain imaging studies show that
brain activation patterns of adult humans looking at or listening to their romantic partners are similar to those taken when the brain is experiencing cocaine-induced euphoria. Insel and other neuroscientists suggest that the neural pathways involved in the pleasurable effects of stimulant drugs may have evolved in part as reward systems for social attachment.

Exuberance also unites members of a group by inducing a synchronous emotional state: it rouses a community to act together and to realize its best and common interests. Passionate leadership at the community or national level, for example, binds us together in essential ways. “
Passions are the only orators which always persuade,” said La Rochefoucauld. “They are like an act of nature, the rules of which are infallible; and the simplest man who has some
passion persuades better than the most eloquent who has none.” In times of adversity, inspired leadership offers energy and hope where little or none exist, gives a belief in the future to those who have lost it, and provides a unifying spirit to a splintered populace. At no time in recent history has this been more true than for the Americans and British during World War II, when they were led by two remarkably exuberant men, Franklin Delano Roosevelt and Winston Churchill. Both had come from families of influence and privilege but each had, as well, overcome great personal adversity—Roosevelt had struggled with polio and Churchill with
repeated bouts of depression. The same resilience and joie de vivre that helped see Roosevelt and Churchill through difficult illnesses were integral to their success as wartime leaders. Both men were able to draw upon an innate capacity for joy and energy, both found delight in difficult work, and both knew from experience that hardship could be overcome. Both had an infectious wit and optimism, and, observed the British philosopher and historian Sir Isaiah Berlin, they “
conspicuously shared… [an] uncommon love of life.”

To meet Roosevelt, said Churchill, “
with all his buoyant sparkle, his iridescence,” was like “opening a bottle of champagne.” Churchill, who knew both Champagne and human nature, recognized ebullient leadership when he saw it. Roosevelt had utter faith in himself and in the course of his country. “
At a time of weakness and mounting despair in the democratic world,” said Isaiah Berlin, Roosevelt stood out “
by his astonishing appetite for life and by his apparently complete freedom from fear of the future; as a man who welcomed the future eagerly as such, and conveyed the feeling that whatever the times might bring, all would be grist to his mill, nothing would be too formidable or crushing to be subdued.” He had “unheard-of energy and gusto…[and was] a spontaneous, optimistic, pleasure-loving ruler” with an “unparallelled capacity for creating confidence.”