By the early 1960s, after almost a decade of hard work on rII, Benzer was also feeling the Push and the Pull. The gene business was getting so crowded that he thought it would soon be as bad as electronics. Benzer turned forty and looked around him. At Cold Spring Harbor and Woods Hole, more and more toddlers were dragging their diapers in the salt water at low tide. More and more of the fathers and mothers hovering over them were talking about guanine and cytosine, adenine and thymine. Like all parents, they also gossiped about their children’s looks and quirks. The discoverers of the gene found themselves repeating the same observations that parents have always traded at the beach: “Just like his father.” “Where does she get that?” “Two peas in a pod.” “Runs in the family.” “Must be in the blood.” They pronounced these clichés with arched eyebrows and cosmic winks, they put the old phrases in the goosefeet of quotation marks, to acknowledge that they had already waded out some distance into these mysteries.
Benzer and his wife thought their first daughter, Barbie, was delightfully lively. They thought their second daughter, Martha, was delightfully calm. Martha had been a different baby from Barbie from her first week in the crib. Watching them play by the water at Cold Spring Harbor or Stony Beach, Benzer wondered, “Are we doing things that differently, or is it genetic?”
“When you have one child, it behaves like a child,” Benzer told a lecture audience not long ago, accepting the Crafoord Prize in Stockholm for his work on genes and behavior. “But as soon as you have a second child you realize from Day One that this one is different from the other.”
Benzer began to notice that whenever he read something about rII he felt bored, and whenever he read something about behavior and personality he felt alive. He was using what Crick calls the “gossip test.” Crick believes that “what you are really interested in is what you gossip about.” Benzer listened to his own gossip, his wife’s, and his friends’, and he felt the pull of the problem of genes and behavior. His friends felt the pull too; the same subject was on all their minds. When Watson became a lather, some years later, Benzer had an idea for a present. His wife, Dotty, went out, bought it, and wrapped it. Watson opened the box, and there was a pair of baby sneakers with the shoelaces untied.
Back in 1955, when Benzer had just begun his map of the rII gene, Delbrück had predicted that the map would keep him busy for ten years. “He was right,” Benzer wrote in 1966, looking back on his rII adventure in a volume of reminiscences that he and his friends put together for Delbrücks sixtieth birthday. “In 1965 my interest suddenly turned off post-hypnotically, and it is now more than I can do even to think about the subject.” During one single year toward the end of his mapping mania he had published half a dozen papers. That year Delbrück had intercepted a letter that his wife was writing to Benzer’s. Max had added a postscript: “Dear Dotty, please tell Seymour to stop writing so many papers. If I gave them the attention his papers used to deserve, they would take all my time. If he must continue, tell him to do what Ernst Mayr asked his mother to do in her long daily letters, namely, underline what is important.”
Suddenly it was hard for Benzer to think of anything worthy of being underlined. He drove out into the cornfields with Dotty again, and again she supported his decision to start over. His work on rII had gotten more and more exciting, he later wrote, until it dawned on him how many people around him were doing the same things, spinning around the same helix or vortex. “I had almost gone down the biochemical drain. Delbrück saved me, when he wrote to my wife to tell me to stop writing so many papers. And I did stop.”
TEN YEARS after the discovery of the double helix, Benzer began reading omnivorously: everything he could find about the inheritance of behavior. A few of his phage friends were doing the same thing, including Brenner, Stent, and Delbrück. They were arrogant and confident, but considering what they had accomplished in the previous ten years they had a right to be. Crick considered their hubris “a healthy corrective to the rather plodding, somewhat cautious attitude I often encountered when I began to mix with biologists.” Having created a new science, they were racing on. They thought of the problem of instinct as an extension of the problem of inheritance. An instinct, like a gene, is a kind of memory, a gift of time. The gift confers enormous advantages on all those that possess it. We are born knowing a thousand things we could not reinvent in a lifetime if we had to start from scratch. At Caltech, Delbrück used to play chess with the mathematician Solomon Golomb. Delbrück spent sixty minutes to Golomb’s one minute and still couldn’t win. Delbrück’s friends asked him why he kept losing when he gave so much thought to each move. Delbrück said, “I think, but he knows.” Now Delbrück and his followers wanted to solve the secret of inborn knowledge the way they had solved the secret of inheritance. They wanted to take instincts apart the way Benzer had taken apart the gene.
What was new in their approach was the attempt to work from the bottom up and from the inside out. Freud worked by introspection, which is looking from the outside inward. For Freud the brain was a black box. When he spoke about the unconscious workings of the mental apparatus, he added a warning for his readers: “I must beg you not to ask what material it is constructed of. That is not a subject of psychological interest. Psychology can be as indifferent to it as, for instance, optics can be to the question of whether the walls of a telescope are made of metal or cardboard.” “We must recollect,” Freud once admonished his followers, “that all our provisional ideas in psychology will presumably one day be based on an organic substructure.” But Freudians and virtually all of the schismatic sects that split away from the Freudians studied the psyche strictly from the top down and the outside in. One psychologist wrote that as far as he was concerned the skull could be full of cotton.
Benzer read these psychologists sardonically. Far back in his mind he could hear Max Gottlieb’s asperities in Arrowsmith the true scientist hates “guess-scientists—like these psychoanalysts.” Benzer and his circle had found an inner book of symbols that everyone could read, and he hoped their science, unlike Freudian psychology, could build higher and higher on its own foundations.
After Freud, two of the most influential psychologists of the century were John Watson and B. F. Skinner, the founders of behaviorism. Watson and Skinner had decided to proceed not by introspection but by inspection. Science had lifted “the stifling soul cloud” in the study of heaven and earth, John Watson wrote in 1912; now science must lift the cloud from the study of psychology. Watson, Skinner, and their followers tried to see how much they could learn about stimulus and response by conditioning pigeons and rats. For them everything that mattered at the choice points of life came from experience—from environment, from nurture, from outside. John Watson (Watson the behaviorist) made the much-quoted claim that if he were given a dozen healthy babies he would “guarantee to take any one at random and train him” for any job at all, no matter what “his talents, penchants, tendencies, abilities, vocations, and the race of his ancestors.”
“Very few people have any notion of the extent to which a science of human behavior is indeed possible,” B. F. Skinner wrote in a sort of conspiratorial, movement-starting whisper in 1953, the same year Watson and Crick discovered the double helix. By then the behaviorists’ decision to avoid introspection had hardened into the curious view that there is nothing inside us to inspect. Behaviorists had invented a psychology without wants, intentions, or emotions; a psychology—it has been said—without a psyche; a psychology that was all outside. Skinner played with schedules of reward that would get a pigeon to peck at a button. He could space the rewards farther and farther apart and get pigeons to keep pecking until their beaks were worn down to stubs. He was convinced that human beings would have to give up their illusions of mind and soul and emotion, inner life and inner nature, and replace them with stimulus and response. Giving them up once and for all would cure most of the ills of the world, Skinner wrote: “The present unhappy condition of the world may in large m
easure be traced to our vacillation.”
Benzer was not impressed by the behaviorists. Nor did he find what he was looking for in the philosophers; at least not in the kinds of thinkers whom Nietzsche once called with some self-loathing the “knowledge-microscopists,” people who cross-examined their own thoughts in their own skulls, asking “What do I know?” and “How do I know it?” and “How do I know that I know?” Benzer’s friend Gunther Stent loved to read the philosophers, but most of their circle laughed at them and shook their heads: “They need a little help from their friends.”
Every scientist knows the rule called Occam’s Razor: Faced with several competing hypotheses, prefer the simplest one. There is also an unspoken corollary that might be called Occam’s Castle: Faced with several competing places to build a new science, prefer the simplest one. Pick the place that requires the least preparation, the least digging, hauling out, pouring in, and shoring up. In real estate the rule is location, location, location. In science the rule is foundation, foundation, foundation. Where the foundation is firmest, the castle will rise highest. Where the ground is solid, build there, and the universe is so constructed that you will have a view.
A new science had sprung up on the foundations of physics, chemistry, and Morgan’s Fly Room. Benzer and his friends had already added a few stories, always building where the ground was most solid, usually with a sense of very slow and incremental progress, as in the words of the prophet Isaiah: “For precept must be upon precept, precept upon precept; line upon line, line upon line; here a little, and there a little.” Molecular biology is Occam’s proudest and strangest castle. Rising from what is (from the point of view of real estate) one of the world’s unlikeliest places, the Fly Room, it has grown into the single most towering accomplishment of the human mind in the last one hundred years.
Benzer wanted to build on that foundation. He was convinced that there must be genetic differences behind the innumerable quirks of our bodies and minds, and he was sure that these differences must matter at every turn of our behavior, at every one of our choice points. He wanted to find some of these genes and figure out how they make a difference. In those years these were new questions, and their strangeness attracted Benzer like filet of snake. He went into his new problem as if he were stepping into the dark, not sure how many steps there were or if there were any steps at all.
On and off during the first half of the 1960s Benzer read and mused, visiting laboratories, taking courses, looking for a place to start. His bookshelf from that period of his life includes titles ranging from Darwin’s Expression of the Emotions in Man and Animals and Galton’s Hereditary Genius to The Machinery of the Brain, Physiological Psychology, The Physiological Clock, Behaviorism, Behavior of the Lower Organisms, and ABC and XYZ of Bee Culture (33rd edition).
Everyone since the beginning of human thought had been looking for a solid foundation. Socrates in one of his last dialogues before drinking the hemlock complained that arguments about human nature “visibly shift their ground instead of keeping still.” He cried, “Don’t you see that our discussion has gone right round and come back to the point from which we started?”
Pascal wrote, “We burn with desire to find a firm footing, an ultimate, lasting base on which to build a tower rising up to infinity, but our whole foundation cracks and the earth opens up into the depth of the abyss.”
Darwin wrote in his secret notebook, “To study Metaphysics as they have always been studied appears to me to be like puzzling at astronomy without mechanics.” In other words, to approach the great metaphysical questions without understanding how the mind works, without getting inside the anatomy and mechanics of the mind, is an enterprise as hopeless as to approach the motions of the stars and planets without understanding celestial mechanics. “—Experience shows the problem of the mind cannot be solved by attacking the citadel itself,” Darwin scribbled in his notebook. “—The mind is function of body.—we must bring some stable foundation to argue from.”
Genes would be Benzer’s foundation stones. He wanted to build from this foundation to places no one thought the human mind could go. He wanted to find something new about some of the oldest cornerstones of human experience—time, love, and memory—and the oldest questions of heredity, nature, and nurture. He thought about the question at all hours in his physics laboratory at Purdue, and he thought about it in the summers at Cold Spring Harbor, where Dotty always made their rented house a Brooklyn away from Brooklyn. Max and Manny Delbrück, strolling there for dinner, would smile to see Dotty waving at them from the porch amid blowing laundry. Dotty was as down to earth as Seymour, and she anchored him the way Leora anchored Martin Arrowsmith.
Natural philosophers had struggled forever with nature and nurture, nurture and nature, wheeling and wheeling in the fugue of the questions. Their writings were a fumbling of wings in a locked room: whole generations trapped like flies in a fly bottle, or like the bat in D. H. Lawrence’s poem, going
Round and round and round
with a twitchy, nervous, intolerable flight
Benzer wanted to work from the gene to the neuron to the brain to behavior, and he hoped to dissect them all the way he had dissected the gene. While he thought and read, he asked Dotty to buy brains at the butcher’s shop: sheep, cow, goat, pig, and chicken brains. One by one she brought them home, and one by one he dissected them, usually in the middle of the night. Afterward, he ate them.
PART TWO
Konopka’s Law
Things are always best in their beginning.
—BLAISE PASCAL,
Lettres Provinciales
CHAPTER SIX
First Light
I’ll tell you how the Sun rose
A Ribbon at a time.
—EMILY DICKINSON
Everyone who ever lived … lived at a moment of equal astonishment.
—RICHARD POWERS,
Galatea 2.2
BENZER FOUND his next destination in a little book called The Machinery of the Brain, by Dean E. Wooldridge, in which a drawing of the furrowed lobes of the human brain loomed attractively on the title page like attainable mountains.
In The Machinery of the Brain, Benzer read about the early experiments of a biologist at Caltech named Roger Sperry. Sperry had cut the optic nerves of a toad and reconnected the left optic nerve to the right half of the toad’s brain and the right nerve to the left half of its brain. Toad nerves can be cut and spliced like wires; once human nerves are severed, unfortunately, they will not reconnect (although the science that Benzer helped to start may change that yet). An optic nerve is actually a bundle of tens of thousands of nerves. These fibers cross and twist and wind around one another as if none of them had been sure when they first grew in the embryo that they knew the way between the eye and the brain. Obviously they do find their way in the embryo. They cannot find their way again in an adult human being, since the nerves will not grow; but Sperry wanted to see if they could find their way a second time in a fully grown toad.
A few weeks after the operation, Sperry was amazed to find that the toad acted like a normal toad. When a fly came down within its reach, the toad darted out its tongue. Somehow those tens of thousands of fibers in each optic nerve had found their way, and the toad could see again. The toad had only one problem: if a fly came from the right, it stuck out its tongue to the left, and if a fly came from the left, it stuck out its tongue to the right.
In The Machinery of the Brain, Benzer also read about Sperry’s experiments with cats. The optic nerves from a cat’s right and left eyes meet briefly on their way to the two hemispheres of the brain and then part again. At their meeting point, the optic chiasma, they share some of their information. Human beings have an optic chiasma too. With a scalpel, Sperry cut through the optic chiasma. Again he let his subject recover from the operation. Now he led the cat to a choice point, the way Benzer would later do with his own subjects in the countercurrent machine. There might be two doors, one marked with a cir
cle and the other with a square. The cat would study these doors through one eye—Sperry had given it an eye patch—so the image of the circle and the square would travel from one of the cat’s eyes to one half of the cat’s brain. And after a few tries the cat would learn to choose the door with the circle because that one led to a pellet of food.
The cat could learn this kind of lesson through either eye, and it would choose the circle again the next time even if Sperry switched the eye patch. Even though one eye had sent its messages to one hemisphere, both hemispheres had somehow learned the lesson. Sperry assumed that the lesson had been shared across the corpus callosum, the thick bundle of nerve fibers that connects the hemispheres of the brain in cats and in human beings. He cut the corpus callosum; and when he switched the cat’s eye patch, the cat did not know which door to choose, the circle or the square. If the left brain had learned the lesson, the right brain had not; and if the right brain had learned the lesson, the left brain had not. Sperry could even teach the left brain to choose the circle and the right brain to choose the square, and the door the cat chose would depend on which eye saw the choice point.
Time, Love , Memory Page 8