by Leah Wilson
So what was going on? After repeated trials, Darwin was intellectually prepared for the puff adder’s attack. His brain knew the glass barrier provided absolute protection. He wasn’t surprised by the sudden appearance of the animal; he knew the snake would strike. But whenever it did, that certain knowledge evaporated and Darwin flinched. Fear got the better of him.
When it comes to understanding fear, we have an advantage that Darwin didn’t. He could only observe the behavior of animals, including himself, and record the ways in which they all responded to danger or perceived threats. He could not see what was happening inside the bone box of the skull. Thanks to technology (fMRIs) we can actually watch a living brain at work. We can see which parts of the brain are active in response to pictures of spiders, snakes, and angry faces. We can, essentially, see fear happening inside our heads.
One thing that these studies have revealed is the outsized contribution to survival played by a little biological gizmo the size and shape of an almond called the amygdala.5 It might not look like much, but when it comes to danger, it is the emergency first responder.
Remember the symptoms of fear that Tris experiences as she prepares to jump? They are all part of the wave of responses the amygdala activates. It is the amygdala that prods the hypothalamus to release the cascade of chemicals and nerve impulses that jolt the entire system into fight-or-flight mode.
Her heart was “pounding so fast it hurts.” That rapid heartbeat is a signal of changes through her circulatory system. Blood is flowing faster and more abundantly to the muscles in her arms and legs, the large muscles that are essential to running and defense. Her brain is also getting a richer supply of oxygen and energy through the bloodstream. Meanwhile, her arms are noticeably pale because the capillaries nearest her skin have contracted as part of the system-wide diversion of blood supply.
The “lurch” Tris feels in her stomach could be linked to a quick shutdown of her digestive system. As important as digestion is to survival in the long term, in the short term the energy required for that process can be put to better use elsewhere.
Even the goose bumps that rose on her arms are survival oriented. Granted, human goose bumps may not seem like much of a defense now, but once upon a time, our furrier ancestors might have benefited. Goose bumps are caused by the pilomotor reflex, which is the same reflex that makes a scared kitten puff up to three times its actual size. Appearing bigger can discourage potential enemies and might make the difference between being eaten for lunch and living to reproduce.
Why do all of these fear symptoms happen so fast? Neuroscientist Joseph LeDoux and his colleagues have been studying the role of the amygdala in fear responses and have discovered that certain kinds of sensory information—like sudden, loud noises—aren’t processed and interpreted. Instead, they are transmitted directly to the amygdala, jolting it into action. This fear circuit takes only milliseconds.6 Since the information traveling on this shortcut isn’t processed by the conscious part of our brains, the reactions aren’t under conscious control; everything that happens, from changes in blood flow to the eruption of goose bumps, is involuntary.
Short of surgically removing the amygdala, there is no way to break this fear circuit. You can’t “decide” not to respond because the reasoning, decision-making part of your brain isn’t consulted. That’s why Darwin couldn’t stand still when the puff adder struck; he was being protected by a part of his brain that didn’t take time to think things over. It was getting quick-and-dirty information—and acting immediately to keep him safe.
So, one important answer to the question about how fear gets into your head is this: you are born with it. Even newborns exhibit the fundamental fight-or-flight protective responses long before they can fight or flee. But there is another way that fear gets into our heads: we learn it.
FEAR IS A LEARNED RESPONSE, OR HOW TO TERRORIZE A BABY IN A FEW SIMPLE STEPS
Little Albert was about nine months old when he was used (and, it must be said, abused) as the subject of a psychological experiment done in 1920. If you have ever been around a little human at that age, you know they are curious creatures, interested in the world, and it can be a full-time job keeping them out of harm’s way. This is how I imagine Little Albert to have been, and when I watch the movies made in the laboratory, when I see how interested he is in dogs, bunnies, white rats—even fire—I see a little brain learning all it can. Through his own experiential exploring (and hopefully with some parental protection), Little Albert would have learned that it’s a bad idea to pet fire or to put his fingers in that part of the doggie. He would have learned about real dangers in the real world. But the researchers intervened and exposed him to a process that changed how he learned about fear.
While Little Albert was just looking around the room, thinking his little baby thoughts, the researchers banged on a metal pipe and made the sort of noise that causes the amygdala to go to red alert. Little Albert was—like you, me, or Charles Darwin—unable to control that fear response. Then the researchers started systematically linking that noise, and the fear response it evoked, to a little white rat. Before this “fear conditioning” Little Albert was interested in the rat. By the time he had been thoroughly “conditioned,” he reacted to the sight of the rat with fear. It wasn’t necessary to make the noise because his amygdala had learned to associate the animal with the horrific clang. It took no more than the sight of the rat to cause fear in Albert. Even worse, his little brain generalized his experience. At the end of the experiment, Little Albert was terrified of all furry things, even fur coats and Santa’s white beard.
Sad as the story of Little Albert is (and it makes me want to cry), it did point the way to an important possibility regarding the control of fear. If fear can be learned through conditioning, it might also be possible to unlearn it. Through the process known as fear extinction, a fearful person is repeatedly exposed to a stimulus that causes fear. All of these encounters take place in a controlled situation where nothing bad happens. The person is encouraged to be aware that the fear they are experiencing is an overreaction. Eventually the stimulus is “unlinked” from the fear response. Called counterconditioning, this system for unlearning fear essentially erodes the connection in the brain between a stimulus and a response. The technique is used therapeutically to assist those living with PTSD, chronic anxiety, and irrational phobias. While struggling with generalized anxiety, Veronica Roth herself found relief through counterconditioning that helped her retrain her brain.7
FEAR IS CONTAGIOUS, OR SEEING IS FEELING
There is at least one more way that fear gets into our heads: it’s contagious. It doesn’t spread by germs. We catch it via sight. When you see another experiencing fear, you are very likely to experience fear yourself. So fear can spread just fine without help from Jeanine’s hallucinogens, fear serums, or transmitters. There are cells in your brain dedicated to making sure you catch fear from others. Those cells are called mirror neurons. As an Erudite scientist explains in Insurgent, “Mirror neurons fire both when one performs an action and when one sees another person performing that action. They allow us to imitate behavior.”
Brain scans have caught this special category of cells at work and made it clear that they offer a wonderful advantage: they make it possible to learn that it is a bad idea to touch a hot stove without getting blistered fingers ourselves. Merely observing another’s experience gives the brain the information that it needs to make the association between stimulus and response. That is a significant benefit in terms of survival.
Remember when Tris was on the brink of becoming the first initiate to master her fear and jump into the Dauntless headquarters? Mirror neurons—and Jeanine8 says in Insurgent that Tris has an unusually high number of them—were active in her brain. Not only was her amygdala causing her to experience fear in response to direct sensory experience, the mirror neurons in her brain were registering the example of the poor, fallen girl.
But “catching fear” is
n’t the only function of mirror neurons. They are also essential to developing the social bonds that link us. The uncontrollable inclination to imitate others is called modeling by psychologists, and it is a shortcut to learning the ropes of social communication and cooperation. Mirror neurons don’t just make us flinch when we see someone else stub a toe, they also make babies react to facial expressions by imitating them. Those shared facial expressions are the foundation of social bonds.
Our mirror neurons may have originally evolved to help us avoid danger, but they have grown along with other aspects of our human brains, like the ability to think symbolically and use language. And when we hear a story, watch a play, or read a book, they make it possible for us to become emotionally invested in the lives of imaginary characters—like Tris, Tobias, and the other people we “know” through reading and observing in our imaginations while we read Divergent. It amazes me. When we read about Tris and her mirror neurons, mirror neurons are firing in our brains, too.
This is why we can become immersed in a story and why the characters in it become so real to us. This is why, according to recent research, reading fiction makes us more empathic. Reading stimulates the activation of mirror neurons, the same brain cells that are key to caring about others. If you were horrified and saddened by the treatment of Little Albert, if you cringe when a contestant on Total Blackout weeps and gropes in the darkness, if you cried at the end of Tris’ story, you may have exhibited another capacity of the brain: the ability to experience the suffering of another. You experienced the power of mirror neurons to make us empathize.
Unfortunately, there is a limit to the power of mirror neurons, and it is related to their power to connect to those around us. Our mirror neurons fire more easily when we see a face like the faces we already know, which, in turn, makes it easier for us to communicate and cooperate, but what happens when we encounter a stranger, someone different from ourselves? In one telling experiment, researchers hooked subjects up to EEG monitors and showed them a series of videos of men picking up a glass of water. When the person in the video was of a different race or ethnicity from the subject, the subject’s mirror neurons were less likely to activate.9 Less activity can translate into less empathy, and reduced empathy can change the way we respond to others. When someone knocks on the door and requests help, activated mirror neurons can mean the difference between a helping hand and rejection. Without an empathic connection, all that remains is an unknown, and we have already discussed how terrifying the unknown can be.
It is easy to confuse difference with danger and be afraid. When that fear is coupled with a justification, no matter how flimsy, violence can result. Fight or flight? When it comes to encounters with other human beings, all too often, the choice is fight.
THE FUTURE CHICAGO EXPERIMENT, OR LOW-TECH, SLOW-FORM GENETIC ENGINEERING
When Tris escapes Chicago in Allegiant, she discovers that her Divergence isn’t a flaw, it is the desired result of a generations-long experiment with the goal of “healing” genetic damage. The cause of that damage? The direct manipulation of genes. David refers to it as “editing humanity,” but we call it genetic engineering.
Genetic engineering is the introduction or elimination of DNA in an organism. Say you want a plant that glows in the dark. You might try to take the firefly genes responsible for bioluminescence and introduce them into a plant’s DNA. More usefully, if you want to study a human illness but need an animal model, you could use genetic engineering to create mice with a similar problem by inactivating key genes. These “knockout” mice are providing insight into cancer, heart disease, aging, and anxiety. Outside of the laboratory, genetic engineering is playing an increasing role in agriculture, creating crops that are more disease or drought resistant and even “immune” to herbicides. This is, of course, very controversial. Many worry about unforeseen consequences. And that brings us back to David and the origins of the future Chicago project.
Scientists in Divergent’s world once tried to “knock out” the genes linked to negative traits like cowardice, dishonesty, and low intelligence. The results of that direct approach were catastrophic. On the individual level, eliminating a trait like cowardice resulted not only in courage, but in aggression and violence. Or as David explains to Tris, “Take away someone’s aggression and you take away their motivation . . . Take away their selfishness and you take away their sense of self-preservation” (Allegiant). On the social level, the Purity Wars erupted.
Learning from this, the Bureau of Genetic Welfare decided to take a slower, less-invasive approach to genetic “improvement.” They are willing to wait for generations to pass in order to eventually produce a higher number of “genetically healed humans.” But slow approach or not, future Chicago is still another genetic experiment like the one that caused the Purity War to begin with. If we evaluate that experiment’s design from a purely scientific point of view, it’s a terrible plan, and unlikely to produce the desired results.
Basically, the future Chicago is a selective breeding program. Selective breeding is a very ancient technology; humans have practiced it since the domestication of dogs and the dawn of agriculture. Every delicious pineapple, every fast-growing turkey with overdeveloped breast muscles, every potato destined to be french-fried is the result of generations of tinkering with genes via selective breeding.
Human beings are just as malleable as turkeys or pineapples. We are organisms that reproduce, passing along genetically coded traits. Some of those traits are easy to see, like eye color. Others are not so visible, like the inclination to take risks. Remember Darwin and his willingness to go sail off and slog through jungles? It is possible that he was influenced by his own “adventurer” gene. Even smoking cigarettes—that weird habit of the Candor—may be an expression of DNA. Research indicates that willingness to try the first cigarette is tied to a risk-taking gene, and addiction is also a genetic predisposition.
Nothing is simple when it comes to genes, and tinkering in hope of enhancing one trait can cause the emergence of another, unexpected trait, even when that tinkering isn’t done directly to the DNA. A fifty-year-long fox-breeding experiment is great evidence of this. Russian geneticist Dmitry Belyaev focused his breeding program on a particular behavioral trait—tameness. Only the tamest members from each litter were allowed to mate. The resulting generations of foxes were tamer. They were very friendly and sociable around humans. But they also had floppier ears, a wider variety of coat colors, and shorter noses. If you selectively breed for tamer foxes, you end up with an animal that looks a lot like a domestic pooch. Judging by the products—like Jeanine and Eric—of the Bureau’s long-term breeding program, future Chicago is full of unintended consequences.
What about the intended goal, the production of those desirable Divergents? Future Chicago is doomed to be less successful than the fox-breeding experiment for several reasons. First of all, there is no geneticist making the decisions about which of the subjects will mate and with whom. They keep track of the family trees, but they don’t do what Belyaev did with the foxes by controlling which foxes mated. If the goal is Divergence, then a faction system that encourages mating from a limited gene pool where a single trait dominates is counterproductive. It’s like trying to produce “tame” foxes by breeding from a closed-group selection of foxes that may or may not show any tendency to tameness. And all that is further complicated by the “Choosing Ceremony,” where the breeding animals choose which gene pool to enter. (If the very idea of “captive breeding” of humans revolts you, it should. Ethical scientists would never behave in that way. But there is nothing ethical about science as practiced in the Divergent trilogy.)
Since the faction system makes the production of Divergence less efficient, why did the Bureau of Genetic Welfare build it into the social fabric of future Chicago? David tells Tris that this social order, with its clear cultural divisions, was meant to “incorporate a ‘nurture’ element.”
Nurture matters, there is no doubt
about that. A baby raised in an environment where sharing and generosity are valued is more likely to imitate those behaviors (go mirror neurons!). A baby raised in a culture where the rule is “spare the rod, spoil the child” is more likely to use violence to solve problems (mirror neurons, no!). The factions are designed to enhance the traits valued in each of those “cultures.” And nurture doesn’t only influence behavior. The effects of nurture (or the lack of it) can be inherited.
It’s an amazing fact: if your grandmother or grandfather had a stressful life, you may be more prone to anxiety. The change isn’t genetic; it is epigenetic. That prefix epi-means “on or above” and that’s where your grandmother’s hard life has left its traces—in proteins that encode on the outside of the chromosomes she passes down and that can affect the expression of certain genes. We know that environmental factors, like stress, can influence which genes get turned on and which ones don’t. This may be one reason why stress can have such long-term effects on health: it actually can cause cells to grow abnormally and result in disease, even cancer. That is bad enough. That those stress-induced changes can move right along, borne by sperm and egg cells, into future generations is even worse.
There is new and dramatic evidence that fear itself can be inherited due to epigenetic transfer. Researcher Brian Dias conditioned a group of male mice to associate a specific smell with painful shocks.10 (This is similar to the fear conditioning of Little Albert.) Later, those male mice fathered litters of pups, which shared their fathers’ fear reaction to that scent without ever experiencing the pain. Those pups were born “knowing” what their fathers had learned the hard way. While the actual mechanics of this transference are still a mystery—this is far from settled science—it is clear that an environment rich in fear can have a remarkably lasting impact.
