Try to rise above the petty things I run into
I think of love when I do everything I do
Love is about feeling that there is something bigger than just ourselves and our own worries and existence. Whether it is love of another person, of country, of God, of an idea, love is fundamentally an intense devotion to this notion that something is bigger than us. Love is ultimately larger than friendship, comfort, ceremony, knowledge, or joy. Indeed, as the Four Wise Ones once said, it may be all you need.
Romantic love is typically blind, as Maugham notes; we feel it for those we don’t really know. And it tends to be very me-oriented: I love her because of the way I feel when I’m with her; because I have fun when I’m with her; because I find her beautiful, sexy, smart, funny, and so on. A more mature love comes when we care more about that person’s happiness than we do our own—the selfless love that parents show toward children, a willingness to do without so that the child or our mate can do with. Romantic love drives us to be with the other person at all costs; mature love drives us to want to see the other person happy, even if that means not being with us. “If you love somebody, set them free,” as Sting famously sang.
From an evolutionary perspective, it may seem that putting others before oneself doesn’t make sense—after all, the name of the evolutionary game is to put your genes first. How in the world could not putting them first end up getting more of them in circulation? The apparent paradox of this kind of altruism has an explanation in evolutionary science. Because we share half our DNA with our siblings, sacrificing ourselves for a sibling or a sibling’s offspring still helps some of our DNA, some of our genes, to survive. The same argument is made for homosexuality, which on the surface of things might seem to be maladaptive. But if a gay brother or sister cares for a sibling’s children, he or she is still helping to promote the family’s genes. Altruism also helps to diffuse potentially deadly conflicts. During harvest festivals celebrated by Southwest American Indians, for example, foodstuffs are redistributed equitably among neighboring tribes, eliminating what could be deadly food-jealousy wars.
Altruism is not limited to humans—animals show it as well. Vervet monkeys delivering alarm calls to warn others are putting themselves at risk (by attracting the attention of the predator) in the service of protecting their kin. Dolphins have been shown to aid other species who are injured by helping them to get to the water’s surface or to shore.
Some evolutionary biologists argue that love developed as an adaptation that helped increase the likelihood that human offspring would receive the care they require. Humans have the longest maturation period of any animal. Baby mice at three weeks can be left completely alone by the parents and survive. By twelve weeks dogs are self-sufficient. But leave a nine-month-old human infant alone and—even if no harm comes to the child—you can be arrested for child endangerment. Human children need at least a decade of care and instruction. Unlike spiders, bees, and birds, who have instructions encoded in their brains for building their webs, hives, and nests, human infants learn by being taught explicitly. Using the same phrase that Joni Mitchell used to describe humans, the anthropologist Terrence Deacon has referred to this as de-evolution, in that the brain itself carries fewer and fewer preprogrammed instructions (compared to other primates and other mammals), and culture and experience take on a greater role in shaping education and behavior. This appears to be related to humans’ fantastic adaptability and ability to thrive in disparate environments, far more so than apes and monkeys. The band Devo (named for the principle of de-evolution) satirically wrote in their song “Jocko Homo”: “God made man, but he used the monkey to do it.” Or as XTC sang, “We’re the smartest monkeys.”
Across all species, young brains are more sensitive to environmental input and more resilient in recovering from brain injury than older brains. This reflects a parsimony on the part of evolution: Rather than building into genes and brains information that is ubiquitous and readily available in the environment, brains are configured such that they can incorporate regularities in the environment, learning through exposure. They do this through the initial overproduction of neurons that are later selectively pruned (in a kind of Darwinian selection process). The system is thus designed to configure itself. It needs to, because as we grow, our brains need to adapt. For example, as we grow taller and heavier, we need to adjust the force we apply to walk. As our eyes grow farther apart (because our head gets bigger), we still need to reach and grasp, and so the brain must take into account these differences in the binocular disparity. If we were designing the brain for efficiency, we would create a system that can learn rules, can map itself, and can respond to the particulars of the environmental input it receives. This efficient parsimony also confers flexibility in the case of unusual circumstances. For example, an organism born with one functioning eye instead of two maps all the input from that one eye to the entire visual cortex (including regions normally reserved for projections from the other eye)—this way the cortical real estate for the nonworking eye isn’t sitting empty.
The brain learns music and language because it is configured to acquire rules about how musical and linguistic elements are combined; its computational circuits (in the prefrontal cortex) “know” rules about hierarchical organization and are primed to receive musical and linguistic input during the early years of development. This is why a child who is denied exposure to music or language before a certain critical age (believed to be somewhere between eight and twelve years old) will never acquire normal music or language skills—the pruning process has already begun, and those neural circuits that were waiting to be activated become eliminated. Certain universals of music suggest that the innate structures themselves contain loose constraints for how music will be represented. Among these are the octave, the fact that all musics work with a set of discrete pitches, and the ubiquity of simple rhythmic ratios (the durations of musical notes across disparate styles and cultures tend to occur in ratios of 2:1, 3:1, or 4:1, not more complex ratios such as 17:11).
The enlarged role of education of the human child stands in stark contrast to any other species. And across history, song has been one of the primary ways in which life lessons are taught. Our ancestors discovered that well-formed songs, combining musical and rhythmic redundancies with lyric messages, facilitate both the encoding and transmission of important information—knowledge songs. But it was love songs and the feelings of love that created the social structure in which we bring up children. Men and women form pair-bonds to the lilts of love songs and mutually ensure the care and nurturing of children.
Humanlike pair-bonding and monogamy are rare in the animal kingdom. In the vast majority of the 4,300 species of mammals in the world, adult males and females tend to be solitary, coming together only to copulate; males don’t pair-bond with the mothers of their offspring and they don’t provide paternal care. Even in the most social mammals, such as apes, lions, wolves, and dogs, there is no evidence that males even recognize their own offspring.
In humans, although polygyny (long-term simultaneous sexual relationships between one man and two or more women) has existed as a rare behavior for thousands of years, the dominant mode of relationships is of monogamy, or at least serial monogamy. This requires that we establish bonds and feelings of intense attachment; love and its neurochemical correlates can be seen as the evolutionary adaptation that makes these long-term bonds possible. Once the adult male-female love mechanism is in place, it can be easily adapted for parent-child love. In fact, Ian Cross quips, love serves an important function there—human infants can be noisy, fussy, and a lot of trouble, and love for them may be the only thing that prevents many parents from killing their children.
Love and altruism take on a different quality in humans than in animals (as do many other of our behaviors) because of our awareness of them, our self-consciousness. We can plan how we want to demonstrate our love, we can promise to love. Our perspective-taking ability helps us to r
ecognize that we have to win over the skepticism of our potential mate.
Some readers may object that when considering the survival of the species, and evolutionary adaptations, love does not appear all that important compared to some of the other attributes we’ve seen in The World in Six Songs. For example, the drive toward knowledge seems clearly essential—those individuals who enjoyed learning were better able to adapt to changing environmental and social conditions. (And as a consequence, they were favored by natural selection.) Knowledge songs developed as an efficient way to encode, preserve, and transmit information. As early or protohumans left the shelter of the trees for the open savannah, exposing themselves to predators, the drive toward friendship allowed for us to navigate complex social and interpersonal exchanges. Comfort songs helped to reassure infants and others with whom we weren’t in physical contact that we were nearby, and they helped to pick us out of periods of sadness by reminding us that others too had felt sad and recovered.
Joy songs began as expressions of our own emotional states, signaling to those around us either a positive outlook or the possession of food and shelter resources. Neurochemical boosts associated with joyful singing helped to reinforce joy as a signal for mate selection. Religion and its songs served to bind animal rituals into systems of belief, and ultimately helped to systematize and socialize feelings of hope and faith.
Love, as intensely as we feel it today, and as much attention as it receives in popular culture, art, and daily conversation, would seem the least important of these, a titillating but nonadaptive neurochemical high similar to the one we get from cocaine, marijuana, a fine Château Margaux, or a good double espresso. If love is viewed only narrowly as romantic love, then it is probably not a cornerstone in the creation of human nature. But love in its larger sense—the sweeping, selfless commitment to another person, group, or idea—is the most important cornerstone of a civilized society. It may not have been important for the survival of our species as hunter-gatherers and nomads, but it was essential for the establishment of what we think of today as human society, what we regard as our fundamental nature. Love of others and of ideals allowed for the creation of systems of courts, justice that is meted out to all members of society equally (without regard to financial status or race), welfare for the poor, education. These fixtures of contemporary society are expensive in terms of time and resources; they work because we believe in them, and are willing to give up personal gain to support them.
I mentioned “I Walk the Line” as an example of a knowledge song, because the singer is reminding himself to “toe the line,” to be true. But of course, it is also a powerful love song, a song celebrating a commitment to something above the passing emotions of lust.
Our love for another person, that special someone, a single love interest, pulls us out of ourselves and lifts our thoughts to a grander scale: How can I make the world better for this person? When I was in my twenties, the only love I experienced was the immature, selfish love of “I love her because she makes me feel good. I want to make her happy so that she’ll stay with me.” Now, at fifty, I think about the woman I love in terms of what she wants. I want to make her happy because I can’t be happy when she is unhappy. We discover that the act of giving love is more powerful than getting the hug you need—if we can get over our own hunger for love, then we have reached the state of pure love, of being connected to a larger ideal, bigger than our own individual life.
Love songs, like all art, help us to articulate our feelings. They often use metaphorical language (“I’m on fire,” “I will climb the highest mountain”) to help us see our emotions from a different perspective. They stick in our heads to remind us, as the emotions ebb and flow, of what we once felt. And above all, they raise the feelings to the level of artistic expression—imbuing them with an elegance and sophistication that helps us strive for them even when the going gets tough.
To understand where love songs came from, it is necessary to go back in evolutionary history and ask two questions. First, of all the senses that could do this work, why does sound have such an important role in our emotions (or, in other words, what are the evolutionary origins of hearing and music)? Second, how did the evolutionary changes that gave us the musical brain give us the sort of consciousness that is required to compose songs, to create art and science, and to build functioning societies?
The hair cells that we have in our ears are found in all vertebrates, including fish, and are structurally and functionally similar to those found on the legs and bodies of many insects (where they are called sensilla). When a grasshopper moves its leg, its hair cells are stretched and help to indicate the position and location of the leg. They are also sensitive to air, water, and other currents, to help detect the presence of an object approaching. This points to the phylogenetically early use of hair cells not just for detecting changes in pressure, which led to hearing in mammals and fish, but changes of position, which led to the vestibular system, our sense of balance. Hair cells are so sensitive that a stretching or movement of only 100 picometers causes them to fire—that’s 1/100,000,000 millimeters, or 100,000 times smaller than a chromosome and 10 times smaller than the radius of a hydrogen atom.
The eardrum is a thin membrane stretched out taut inside our ears, and changes in pressure—whether in air, water, or another medium—cause it to wiggle in and out. This pattern of wiggling eventually sends signals to a snail-shaped organ in the inner ear called the cochlea, which is lined with hair cells much like insects’ sensilla. The human cochlea is so sensitive that it can detect vibration as small as the diameter of an atom (0.3 nm ) and it can resolve time intervals down to 10μs—if a sound ten feet away from you moves even two-and-a-half inches to one side, you can detect that movement just by the difference in the sound’s arrival time at your two ears. The ear detects energy levels a hundredfold lower than the energy of a single photon. Hearing is so sensitive that some species can hear the footsteps of the insects that they seek to eat.
The advantage of hearing over other senses, such as vision for example (as I mentioned in Chapter 2) is that sound transmits in the dark, travels around corners, and can reach us when there are visual obstacles between us and what we want to hear. Sound constitutes an effective early warning system for something approaching us—a boulder rolling uncontrollably down a hillside, a predator stepping on a twig outside our cave, and so on. As part of the early warning system, our hearing sense also has immediate neural connections to our startle response, and detects even the slightest change in background noise in the environment.
Evolution might well have found other ways for us to gather information about the environment rather than the senses we know. Indeed, some animals employ systems that are exotic compared to ours. Sharks have an electrical sense—a sensory system that detects electrical fields produced by the neuromuscular activity of potential prey. Bees, ants, turtles, salmon, sharks, and whales use a magnetic sense for orientation. Indigo buntings possess a celestial compass that allows them to fly at night to find north; through evolution, they have internalized the fact that the entire sky revolves around Polaris, and so they navigate based on the one star that doesn’t change position in the night sky. Interestingly, bunting genes don’t specify which star is the North Star, only that the invariant star should be treated as north (allowing for the possibility that buntings could navigate throughout the northern hemisphere without having to develop a separate mechanism for different latitudes). Experiments by Stephen Emlen with indigo buntings in a planetarium demonstrated that the birds will treat any star as the reference point if it stays stationary.
Given that evolution gave all vertebrates a sense of hearing, it isn’t obvious that this would develop into something as complex as music, but evolution moves slowly. Complexity is built up stone by genetic stone through small adaptations, each in itself perhaps imperceptible, building to a grand crescendo. As hearing became refined, and responsive to environmental events, selection pressures
made all vertebrate brains sensitive to differences in pitch, spatial location, loudness, timbre, and rhythm, the fundamental ways in which objects can be differentiated from one another through sound. This is not so surprising, because the basic structure of neurons and synapses, the chemical soup of neurotransmitters, is common to all vertebrates.
The basic function and structure of genes is also common to all animals. Genes serve to determine, constrain, and guide cells so that they develop properly and perform their essential functions; they contain instructions, like a blueprint, that neurons and other cells follow. As fetal and infant brains develop, certain common proteins encoded in DNA, such as netrins and homoetic gene products, even dictate how neurons will connect with one another along specific pathways that are analogous in animals as different as roundworms, insects, birds, and mammals. The genetic instructions for neural development are both so powerful and so flexible that they can even guide neural connections to the right places when part of one brain is transplanted into another. Evan Balaban removed the auditory cortices from Japanese quail embryos and surgically implanted them into the brains of embryonic chickens. Not only do the grafts link up anatomically with the new host brains, but the host birds act in ways that demonstrate they have incorporated the donors’ hardwired propensities—specifically, the chickens make vocalizations like quails, not like chickens, even when they are raised by other chickens.
Auditory pathways that are comparable to ours exist even in reptiles and birds. One interesting similarity of auditory system architecture is tonotopy. This means that frequency-selective neurons in the auditory cortex are configured so that low notes activate one end of it and high notes the other—the cortex is literally laid out like a piano keyboard! Tonotopy has been seen in the guinea pig, squirrel, opossum, ferret, tree shrew, marmoset, owl monkey, macaque monkey, rabbit, cat, and bush baby, plus many reptiles and birds. But even though these animals and humans share such tonotopic organization, there remains disagreement among researchers about animals’ ability to differentiate pitches. It is clear that they can distinguish low tones from high tones, but as tones get closer together, it seems that many animals don’t possess the same resolution that humans do: Three consecutive tones in our musical scale may all sound like the same tone to a marmoset, frog, or carp.
The World in Six Songs: How the Musical Brain Created Human Nature Page 23