Phantoms in the Brain: Probing the Mysteries of the Human Mind (33 page)

So what's the bottom line? The one clear conclusion that emerges from all this is that there are circuits in the human brain that are involved in religious experience and these become hyperactive in some epileptics. We still don't know whether these circuits evolved specifically for religion (as evolutionary psychologists might argue) or whether they generate other emotions that are merely conducive to such beliefs (although that cannot explain the fervor with which the beliefs are held by many patients). We are therefore still a long way from showing that there is a "God module" in the brain that might be genetically specified, but to me the exciting idea is that one can even begin to address questions about God and spirituality scientifically.

Then to the rolling Heav'n itself I cried, Asking, "What Lamp had Destiny to guide
Her little Children stumbling in the Dark?" And
—
"A blind Understanding!" Heav'n replied.

—The Rubáiyât of Omar Khayyam

For many of the topics we've discussed in earlier chapters—phantom limbs, neglect syndrome and Capgras'

syndrome—we now have reasonable interpretations as a result of our experiments. But in seeking brain centers concerned with religious experience and God, I realized that I had entered the "twilight zone" of neurology. There are some questions about the brain that are so mysterious, so deeply enigmatic, that most serious scientists simply shy away from them, as if to say, "That would be premature to study" and "I'd be a fool if I embarked on such a quest." And yet these are the very issues that fascinate us most of all. The most obvious one, of course, is religion, a quintessentially human trait, but it is only one unsolved mystery of human nature. What about other uniquely human traits—such as our capacity for music, math, humor and poetry? What allowed Mozart to compose an entire symphony in his head or mathematicians like Fermat or Ramanujan to "discover" flawless conjectures and theorems without ever going through step−by−step formal proofs? And what goes on in the brain of a person like Dylan Thomas that allowed him to write such evocative poetry? Is the creative spark simply an expression of the divine spark that exists in all of us?

Ironically clues come from a bizarre condition called "idiot savant syndrome" (or, to use the more politically correct phrase, the savant syn−

drome). These individuals (retarded and yet highly talented) can give us valuable insights about the evolution of human nature—a topic that became an obsession for some of the greatest scientific minds of the last century.

The Victorian era witnessed a vigorous intellectual debate between two brilliant biologists—Charles Darwin and Alfred Rüssel Wallace. Darwin, of course, is a household name. Everyone associates him with the discovery of natural selection as the main driving force of organic evolution. It is a pity that Wallace is almost completely unknown except among biologists and historians of science, since he was an equally brilliant scholar and independently came up with the same idea. In fact, the very first scientific paper on evolution by natural selection was presented jointly by Darwin and Wallace and communicated to the Linnean Society by Joseph Hooker in 1850. Instead of feuding endlessly over priority, as many of today's scientists do, they cheerfully acknowledged each other's contributions and Wallace even wrote a book called
Darwinism,
championing what he referred to as "Darwin's" theory of natural selection. Upon hearing of this book, Darwin responded, "You should not speak of Darwinism for it can as well be called Wallacism."

What does the theory state? There are three components:8

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1. Since offspring vastly outnumber the available resources, there must be a constant struggle for existence in the natural world.

2. No two individuals of a species are exactly identical (except in the rare case of identical twins). Indeed, there are always random variations, however minute, in body type that arise from the random shuffling of genes that takes place during cell division—a shuffling that ensures that offspring differ from each other and from their parents, thereby increasing their candidature for evolutionary change.

3. Those fortuitous combinations of genes that cause individuals to be slightly better adapted to a given local environment tend to multiply and propagate within a population since they increase the survival and reproduction of those individuals.

Darwin believed that his principle of natural selection could account not only for the emergence of morphological traits like fingers or noses, but also for the structure of the brain and therefore our mental capacities. In other words, natural selection could explain our talents for music, art, literature and other human intellectual achievements. Wallace disagreed. He conceded that Darwin's principle might explain fingers and toes and

maybe even some simple mental traits, but that certain quintessentially human abilities like mathematical and musical talent could not possibly have arisen through the blind workings of chance.

Why not? According to Wallace, as the human brain evolved, it encountered a new and equally powerful force called culture. Once culture, language and writing emerged, he argued, human evolution became Lamarckian—that is, you could pass on the accumulated wisdom of a lifetime to your offspring. These progeny will be much wiser than the offspring of illiterates not because your genes have changed but simply because this knowledge—in the form of culture—has been transferred from your brain to your child's brain. In this way, the brain is symbiotic with culture; the two are as interdependent as the naked hermit crab and its shell or the nucleated cell and its mitochondria. For Wallace, culture propels human evolution, making us absolutely unique in the animal kingdom. Isn't it extraordinary, he said, that we are the only animal in which the mind is vasdy more important than any bodily organ, assuming a tremendous significance because of what we call "culture." Moreover, our brain actually helps us avoid the need for further specialization.9 Most organisms evolve to become more and more specialized as they take up new environmental niches, be it a longer neck for the giraffe or sonar for the bat. Humans, on the other hand, have evolved an organ, a brain, that gives us the capacity to evade specialization. We can colonize the Arctic without evolving a fur coat over millions of years like the polar bear because we can go kill one, take its coat and drape it on ourselves. And then we can give it to our children and grandchildren.

Wallace's second argument against "blind chance giving rise to the talents of a Mozart" involves what might be called potential intelligence (a phrase used by Richard Gregory). Say, you take a barely literate young tribesman from a contemporary aboriginal society (or even use a time machine to garner a Cro−Magnon man) and give him a modern public school education in Rio or New York or Tokyo. He will, of course, be no different from any other child reared in those cities. According to Wallace, this means that the aborigine or Cro−Magnon possesses a potential intelligence that vastly exceeds anything that he might need for coping with his natural environment. This kind of potential intelligence can be contrasted with kinetic intelligence, which is realized through formal education. But why the devil did this potential intelligence evolve? It couldn't have arisen for learning Latin in English schools. It couldn't have evolved for learning the calculus, even though almost anyone who tries hard enough can master it. What was the selection pressure for the emergence of these latent abilities? Natural selection can only explain the emergence of actual abilities that are expressed by the organism—never potential ones. When they are useful and promote survival, they are passed on to the next generation. But what to make of a gene for
latent
mathematical ability? What benefit 133

does that confer on a nonliterate person? It seems like overkill.

Wallace wrote, "The lowest savages with the least copious vocabularies [have] the capacity of uttering a variety of distinct articulate sounds and of applying them to an almost infinite amount of modulation and inflection [which] is not in any way inferior to that of the higher [European] races. An instrument has been developed in advance of the needs of its possessor." And the argument holds, with even greater force, for other esoteric human abilities such as mathematics or musical talent.

There's the rub.
An instrument has been developed in advance of the needs of its possessor,
but we know that evolution has no foresight! Here is an instance in which evolution appears to have foreknowledge. How is this possible?

Wallace wrestled mightily with this paradox. How can improvement in esoteric mathematical skills—in latent form—affect the survival of one race that has this latent ability and the extinction of another that doesn't ? "It is a somewhat curious fact," he wrote, "that when all modern writers admit the great antiquity of man, most of them maintain the very recent development of intellect, and will hardly contemplate the possibility of men, equal in mental capacity to ourselves, having existed in prehistoric times."

But we know they did. Both the Neanderthal and Cro−Magnon cranial capacities were actually larger than ours, and it's not inconceivable that their latent potential intelligence may have been equal to or even greater than that of
Homo sapiens.

So how is it possible that these astonishing, latent abilities emerged in the prehistoric brain but have only been realized in the last one thousand years? Wallace's answer: It was done by God! "Some higher intelligence must have directed the process by which the human nature was developed." Thus human grace is an earthly expression of "divine grace."

This is where Wallace parted company with Darwin, who resolutely maintained that natural selection was the prime force in evolution and could account for the emergence of even the most esoteric mental traits, without the helping hand of a Supreme Being.

How would a modern biologist resolve Wallace's paradox? She would probably argue that esoteric and

"advanced" human traits like musical

and mathematical ability are specific manifestations of what is usually called "general intelligence"—itself the culmination of a "runaway" brain that exploded in size and complexity within the last three million years.10

General intelligence evolved, the argument goes, so that one can communicate, hunt game, hoard food in granaries, engage in elaborate social rituals and do the myriad things that humans enjoy and that help them survive. But once this intelligence was in place, you could use it for all sorts of other things, like the calculus, music and the design of scientific instruments to extend the reach of our senses. By way of analogy, consider the human hand: Even though it evolved its amazing versatility for grasping at tree branches, it can now be used to count, write poetry, rock the cradle, wield a scepter and make shadow puppets.

But with respect to the mind, this argument doesn't make much sense to me. I'm not saying it's wrong, but the idea that the ability to spear antelope was then somehow used for the calculus is a bit dubious. I'd like to suggest another explanation, one that takes us back not only to the savant syndrome that I mentioned earlier but also to the more general question of the sporadic emergence of talent and genius in the normal population.

"Savants" are persons whose mental capacity or general intelligence is abysmally low, yet who have islands of astonishing talent. For example, there are savants on record with an IQ of less than 50, barely able to function in normal society, yet they could with ease generate an eight−digit prime number, a feat that most tenured 134

mathematics professors cannot match. One savant could come up with the cube root of a six−figure number in seconds and could double 8,388,628 twenty−four times to obtain 140,737,488,355,328 in several seconds.

Such individuals are a living refutation of the argument that specialized talents are merely clever deployments of general intelligence.11

The realms of art and music are punctuated with savants whose talents have amazed and delighted audiences through the ages. Oliver Sacks describes Tom, a thirteen−year−old boy who was blind and incapable of tying his own shoes. Although he had never been instructed in music or educated in any way, he learned to play the piano simply by hearing others play. He absorbed arias and tunes from hearing them sung and could play any piece of music on the first try as well as the most accomplished performer. One of his most remarkable feats was to perform three pieces of music all at once. With one hand he played "Fisher's Horn Pipe," with the other he played "Yankee Doodle Dandy" and simulta−

neously he sang "Dixie." He could also play the piano with his back to the keyboard, his inverted hands racing up and down the ivories. Tom composed his own music, and yet, as a contemporary observer pointed out, "He seems to be an unconscious agent acting as he is acted on and his mind [is] a vacant receptor where nature stores her jewels to recall them at her pleasure."

Nadia, whose IQ measured between 60 and 70, was an artistic genius. At age six, she showed all the signs of severe autism—ritualistic behavior, inability to relate to others and limited language. She could barely put two words together. Yet from this early age, Nadia could draw lifelike pictures of people around her, of horses and even of complex visual scenes unlike the "tadpolelike" drawings of other children her age. Her sketches were so animated that they seemed to leap out from the canvas and were good enough to hang in any Madison Avenue gallery (Figure 9.2).

Other savants have incredibly specific talents. One boy can tell you the time of day, to the exact second, without referring to any timepiece. He can do this even in his sleep, sometimes mumbling the exact time while dreaming. The "clock" inside his head is as accurate as any Rolex. Another can estimate the exact width of an object seen from twenty feet away. You or I would give a ballpark figure. She would say, "That rock is exactly two feet, eleven and three−quarter inches wide." And she'd be right.

These examples show that specialized esoteric talents do not emerge spontaneously from general intelligence, for if that were true, how can an "idiot" display them?