The following story offers a vivid example. 

When I first met Jesse, he hadn’t had a full night’s sleep in more than a year. His insomnia was evident in the dark shadows around his eyes, but the blankness of his stare suggested a deeper story. Though only twenty, Jesse looked at least ten years older. He sank onto my sofa as if his legs could no longer bear his weight. Jesse explained that he had been a star athlete and a straight-A student, but that his persistent insomnia had initiated a downward spiral of depression and despair. As a result, he dropped out of college and had to forfeit the baseball scholarship he’d worked so hard to win. He desperately sought help to get his life back on track. Over the past year, he’d been to three doctors, two psychologists, a sleep clinic, and a naturopathic physician. Not one of them, he related in a monotone, was able to offer any real insight or help. Jesse, gazing mostly at the floor as he shared his story, told me he was at the end of his rope. 

When I asked whether he had any ideas about what might have triggered his insomnia, he shook his head. Sleep had always come easily for Jesse. Then, one night just after his nineteenth birthday, he woke suddenly at 3:30 a.m. He was freezing, shivering, unable to get warm no matter what he tried. Three hours and several blankets later, Jesse was still wide awake. Not only was he cold and tired, he was seized by a strange fear he had never experienced before, a fear that something awful could happen if he let himself fall back to sleep. If I go to sleep, I’ll never wake up. Every time he felt himself drifting off, the fear would jolt him back into wakefulness. The pattern repeated itself the next night, and the night after that. Soon insomnia became a nightly ordeal. Jesse knew his fear was irrational, yet he felt helpless to put an end to it. I listened closely as Jesse spoke. What stood out for me was one unusual detail—he’d been extremely cold, “freezing,” he said, just prior to the first episode. 

I began to explore this with Jesse, and asked him if anyone on either side of the family suffered a trauma that involved being cold, or being asleep, or being nineteen. Jesse revealed that his mother had only recently told him about the tragic death of his father’s older brother—an uncle he never knew he had. Uncle Colin was only nineteen when he froze to death checking power lines in a storm just north of Yellowknife in the Northwest Territories of Canada. Tracks in the snow revealed that he had been struggling to hang on. Eventually, he was found facedown in a blizzard, having lost consciousness from hypothermia. 

His death was such a tragic loss that the family never spoke his name again. Now, three decades later, Jesse was unconsciously reliving aspects of Colin’s death—specifically, the terror of letting go into unconsciousness. For Colin, letting go meant death. For Jesse, falling asleep must have felt the same. Making the connection was a turning point for Jesse. 

Once he grasped that his insomnia had its origin in an event that had occurred thirty years earlier, he finally had an explanation for his fear of falling asleep. The process of healing could now begin. With tools Jesse learned in our work together, which will be detailed later in this book, he was able to disentangle himself from the trauma endured by an uncle he’d never met, but whose terror he had unconsciously taken on as his own. 

Not only did Jesse feel freed from the heavy fog of insomnia, he gained a deeper sense of connection to his family, present and past. In an attempt to explain stories such as Jesse’s, scientists are now able to identify biological markers—evidence that traumas can and do pass down from one generation to the next. Rachel Yehuda, professor of psychiatry and neuroscience at Mount Sinai School of Medicine in New York, is one of the world’s leading experts in posttraumatic stress disorder (PTSD), a true pioneer in this field. In numerous studies, Yehuda has examined the neurobiology of PTSD in Holocaust survivors and...

According to Rachel Yehuda, the purpose of an epigenetic change is to expand the range of ways we respond in stressful situations, which she says is a positive thing. “Who would you rather be in a war zone with?” she asks. “Somebody that’s had previous adversity [and] knows how to defend themselves? Or somebody that has never had to fight for anything?”

The history you share with your family begins before you are even conceived. In your earliest biological form, as an unfertilized egg, you already share a cellular environment with your mother and grandmother. When your grandmother was five months pregnant with your mother, the precursor cell of the egg you developed from was already present in your mother’s ovaries. This means that before your mother was even born, your mother, your grandmother, and the earliest traces of you were all in the same body—three generations sharing the same biological environment.1 This isn’t a new idea: embryology textbooks have told us as much for more than a century. Your inception can be similarly traced in your paternal line.

There is, however, a significant biological difference in the evolution of the egg and sperm. Your father’s sperm continued to multiply when he reached puberty, whereas your mother was born with her lifetime supply of eggs. Once her egg cells were formed in your grandmother’s womb, that cell line stopped dividing.3 So twelve to forty or so years later, one of those eggs, fertilized by your father’s sperm, eventually developed into who you are today. In either case, both precursor egg and sperm cells, science now tells us, can be imprinted by events with the potential to affect subsequent generations. Because your father’s sperm continues to develop throughout adolescence and adulthood, his sperm continues to be susceptible to traumatic imprints almost up until the point when you are conceived.4 The implications of this are startlingly vast, as we see when we look at the emerging research.

The pioneering cell biologist Bruce Lipton demonstrates that our DNA can be affected by both negative and positive thoughts, beliefs, and emotions. Dr. Lipton spent decades, as a medical school professor and research scientist, investigating the mechanisms by which cells receive and process information. As a Stanford scholar and researcher from 1987 to 1992, he demonstrated that signals from the environment could operate through the cell membrane, controlling the behavior and physiology of the cell, which in turn could activate or silence a gene. His ideas and discoveries, which were once considered controversial, have since been corroborated by many researchers. As a result of his work with both animal and human cells, we now have a window of understanding into how cellular memory is transferred in the womb from a mother to her unborn child. According to Lipton, “The mother’s emotions, such as fear, anger, love, hope among others, can biochemically alter the genetic expression of her offspring.”