From an evolutionary standpoint, it makes sense that we take special note of people, places, or situations that seem to threaten or benefit our survival; that there is enhanced memory for emotional experiences. Sometimes these emotional moments are especially happy ones, like sunny days spent riding the waves at the beach, or exciting ones, like watching crabs scamper around on the kitchen floor. Other times, they are distressing or frightening events, like watching a parent walk down the hallway and out of our lives. But while happy and exciting events enrich our experience of being alive, frightening events provide important information about staying alive, and so negative emotional memories tend to be more firmly installed in our minds. As psychology researcher Roy Baumeister summarizes in his often cited paper, “Bad Is Stronger than Good”: At least in our minds, “bad emotions, bad parents, and bad feedback have more impact than good ones, and bad information is processed more thoroughly than good.” This is because our brains are wired to keep us alive, not happy, and I doubt a single paper has been written about, nor a single therapy session devoted to, a client’s being unable to forget an extraordinarily joyful time. It is our shockingly upsetting experiences that are most deeply etched in our minds, and only in the last few decades have we come to better understand how the brain makes it so.
In the chapters ahead, the region of the brain we will hear about again and again is the amygdala, or the part of the brain neuroscientist Joseph LeDoux calls the “hub in the wheel of fear.” A small almond-shaped region deep in the brain, the amygdala is a complex structure with many functions, but overwhelming evidence suggests it plays a central role in managing danger. When our senses detect disturbances in the environment—any potential physical or social threat—the amygdala is alerted, and within milliseconds it reacts. The amygdala is, again according to LeDoux, “where trigger stimuli do their triggering.”
One key response that the amygdala triggers is the activation of the HPA axis, or the chain in the neuroendocrine system that consists of the hypothalamus, the pituitary gland, and the adrenal glands. When the HPA axis is stimulated, the adrenal glands release epinephrine, norepinephrine, and cortisol, hormones once commonly called adrenaline because they are produced by the adrenal glands and now more popularly and descriptively known as stress hormones because they help us adapt to stress. In our bodies, stress hormones prepare us for fight or flight, and in our brains, they heighten arousal, attention, and memory. Stress hormones tell our brains to wake up and pay attention, and tell our bodies to get ready to take action. They also tell our brains to remember what we see.
Brain imaging studies show that when we look at intensely emotional material, such as slides of highly pleasant or unpleasant scenes, activity in the amygdala increases; and to some extent, the greater the activity in the amygdala, the better the recall is weeks later. Very low emotional arousal suggests there is nothing significant to pay special attention to, and so to protect our brains from overload, mundane events like showering or driving to work are not likely to be remembered in great detail or for very long. Our brains protect us from another sort of overload by sometimes failing to remember times when we are too emotionally aroused, especially those times that involve the utmost terror or helplessness. This is why victims of shark attacks or violent crimes, for example, may not remember such traumas at all; the events are too overwhelming to assimilate. Moderate stress, however, alerts us to threats in the environment that we perceive we can and should do something about. “There is nothing like a little stress to create strong, long-lasting memories of events,” says neurobiologist James McGaugh.
Emotional learning is powerful and it needs to be efficient, too, because when it comes to survival, there isn’t a lot of room for repeated trial and error. It is for this reason that the amygdala is “quick to learn and slow to forget,” it is said. “Emotional memory,” says LeDoux, “may be forever.” Just as Sam did not need to see his father walk away with his suitcase more than once to remember it decades later, many of us needed to live through only one 9/11 to be haunted by that morning always. Emotional memories stand stronger and longer than everyday recollections, and their vividness makes them feel more real and more central to who we are than the piddling day-to-day. The problem is that when these remembrances are negative, harking back to Charcot, Freud, and Janet, our emotional memories can function as “malignant memories.” They are bad memories that do bad things. The tyranny of the past rules the present and the future as these outsize, tenacious reminiscences take over our autobiographies, and even our lives. Although Sam surely went to birthday parties and rode his bike and ate ice cream and played at the park when he was in the fourth grade, he hardly remembers anything about that year other than the losses and the shocks.
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After Sam’s father left, shiny silver dead bolts appeared on the front and back doors of his house. His mother did not mention them but she had the keys, so—as with many other things—it went without saying: The locks had been installed so Sam’s father could not return. In the months and years that followed, the dead bolts only served as reminders that not once did Sam’s father ever even try to come home. He did call to come get a long wooden table he had bought when he was a bachelor, and although Sam and his mother cleared it off and got it ready to go, his dad never showed. Nor did he come get his slides of Coney Island or his stamp collection, though Sam did not lie on the floor and thumb through its pages on Saturdays anymore. Catching sight of the black leather-bound binder on the bookshelf made Sam feel embarrassed and exposed, like seeing an old teddy bear he felt he could no longer pick up.
Sam’s father did not come back for Sam, either, although one time he took the boy to a matinee. Sam had never been picked up by his father in the driveway before—it was strange—and as he walked to the car, he squinted in the glare of the sun. He could not tell if it was the bright light or the fact that he was working very hard not to cry, but as Sam climbed into the passenger seat he could not unscrunch his eyebrows. He shifted around in his seat not knowing what to say, disturbed by the fact that he had lost control of his face. Sam cannot recall what movie the two saw and he hardly watched it as he sat there gripping the armrests, distracted by the fact that even in the dark theater, he could not unscrew his forehead. What Sam did not know is that those brow muscles are called Darwin’s Grief Muscles because they betray confusion and sadness, even when we try to hide them. As trauma expert Bessel van der Kolk explains, “The body keeps the score,” especially when we have feelings our conscious mind cannot or will not register.
Sam’s parents officially divorced on Valentine’s Day—yes, really—just over two years after his father left. Later Sam would learn that, after the judge ordered his father to pay child support, Sam’s father grumbled to his mother on the way out of the courthouse that he would kill them all first. That evening, Sam’s mother went straight from work to a bar to celebrate with a friend, while Sam kept busy with sixth-grade homework. Around eleven o’clock, she walked in through the back door and let her purse fall on the floor, instead of placing it on the counter as she usually did. Then she rushed to the kitchen and threw up in the sink.
Most children of divorce go from seeing a parent every day to seeing the now absent parent between four and fourteen days a month. About a quarter of kids have little or no contact with the noncustodial parent, usually their fathers, within three years, and that was the case for Sam. Like many children, Sam wished he could see his father more, and he told his best friend that maybe he would go live with him in the summer sometime, that his dad was lonely and wanted him to come. “What in the hell is that about?” his mother asked after hearing the news from the friend’s mother. “Your dad isn’t lonely and you’re not going to live with him. You never even hear from him except for getting cards on holidays.”
For Christmas and Valentine’s Day, Sam’s father tore a ten-dollar bill into two pieces and sent half to Sam and half to Sam’s sister, each tucked into